JP2022117197A - Image capturing lens and image capturing device - Google Patents

Abstract

To provide an image capturing lens which is compact, has a large aperture diameter, and yet offers high optical performance and suppressed view angle fluctuation while focusing, and to provide an image capturing device having the same.SOLUTION: An image capturing lens disclosed herein comprises, in order from the object side to the image side, a first lens group comprising at least two negative lenses, a second lens group having positive refractive power, and a third lens group having negative refractive power. The first lens group is stationary when an object distance changes from infinity to a short distance. Focusing is accomplished by moving the second lens group or second and third lens groups along an optical axis. The image capturing lens satisfies given conditional expressions.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to an imaging lens having a focusing function and an imaging apparatus equipped with such an imaging lens.

In recent years, image pickup devices such as digital cameras have become larger in size and have higher image quality, and along with this, high performance is required for imaging lenses (for example, see Patent Documents 1 and 2) used in these image pickup devices. there is On the other hand, as the use of mirrorless cameras and the like advances toward short flange focal distances, miniaturization of optical systems is also required. In addition, in the case of digital camera systems with interchangeable lenses, the number of cases where not only still images but also movies are shot is increasing. etc. are also required.

JP 2018-205527 A WO2017/168603

As described above, imaging lenses are required to have high performance and be compact. Also, when shooting moving images, it is required to suppress fluctuations in the angle of view during focusing.

It is desirable to provide an imaging lens that is compact, has a large aperture, yet has high optical performance, and suppresses variation in the angle of view during focusing, and an imaging apparatus equipped with such an imaging lens.

A first imaging lens according to an embodiment of the present disclosure includes, in order from the object side to the image plane side, a first lens group having at least two negative lenses and a second lens having a positive refractive power. and a third lens group having negative refractive power. When the object distance changes from infinity to short, the first lens group is fixed, and the second lens group or the second lens group is fixed. Focusing is performed by moving the third lens group in the optical axis direction, and the following conditional expression is satisfied.
-1.05<f2/f3<-0.25 (1)
1.38<β3 (2)
0.2<(R11-R12)/(R11+R12)<0.8 (3)
however,
f2: focal length of the second lens group f3: focal length of the third lens group β3: lateral magnification of the third lens group R1: radius of curvature of the object-side surface of the lens closest to the object R2: the radius of curvature of the lens closest to the object It is the radius of curvature of the surface on the image plane side.

A second imaging lens according to an embodiment of the present disclosure consists of a lens group 1a, an aperture stop, and a lens group 1b in order from the object side to the image plane side, and includes at least two negative lenses. a first lens group comprising at least one positive lens and at least one negative lens; a second lens group having positive refractive power; and a third lens group having negative refractive power. , when the subject distance changes from infinity to short, the first lens group is fixed, and the second lens group or the second and third lens groups move in the optical axis direction for focusing. and satisfies the following conditional expression.
-1.05<f2/f3<-0.25 (1)
|β2|<0.45 (9)
however,
f2: focal length of the second lens group f3: focal length of the third lens group β2: lateral magnification of the second lens group.

A first imaging apparatus according to an embodiment of the present disclosure includes an imaging lens and an imaging element that outputs an imaging signal corresponding to an optical image formed by the imaging lens, and the imaging lens is the It is configured by the first imaging lens according to one embodiment.

A second imaging device according to an embodiment of the present disclosure includes an imaging lens and an imaging device that outputs an imaging signal corresponding to an optical image formed by the imaging lens, and the imaging lens is the It is configured by the second imaging lens according to one embodiment.

In the first or second imaging lens or the first or second imaging device according to an embodiment of the present disclosure, in the configuration including the first to third lens groups, the optical The power of the lens group and the lateral magnification are optimized so as to maintain performance and suppress fluctuations in the angle of view during focusing.

1 is a lens cross-sectional view showing a first configuration example (Example 1) of an imaging lens according to an embodiment of the present disclosure; FIG. FIG. 4 is an aberration diagram showing longitudinal aberration of the imaging lens according to Example 1 during focusing at infinity. 4 is an aberration diagram showing longitudinal aberration of the imaging lens according to Example 1 during focusing at a short distance; FIG. It is a lens sectional view showing the 2nd example of composition (example 2) of the imaging lens concerning one embodiment. FIG. 10 is an aberration diagram showing longitudinal aberration of the imaging lens according to Example 2 during focusing at infinity. FIG. 10 is an aberration diagram showing longitudinal aberration of the imaging lens according to Example 2 during focusing at a short distance; It is a lens sectional view showing the 3rd example of composition (example 3) of the imaging lens concerning one embodiment. FIG. 11 is an aberration diagram showing longitudinal aberration of the imaging lens according to Example 3 when focusing on infinity. FIG. 11 is an aberration diagram showing longitudinal aberration of the imaging lens according to Example 3 during focusing at a short distance. It is a lens cross-sectional view showing a fourth configuration example (Example 4) of an imaging lens according to an embodiment. FIG. 11 is an aberration diagram showing longitudinal aberration of the imaging lens according to Example 4 when focusing on infinity. FIG. 11 is an aberration diagram showing longitudinal aberration of the imaging lens according to Example 4 during focusing at a short distance. FIG. 11 is a lens cross-sectional view showing a fifth configuration example (Example 5) of an imaging lens according to an embodiment; FIG. 12 is an aberration diagram showing longitudinal aberration of the imaging lens according to Example 5 when focusing on infinity. FIG. 11 is an aberration diagram showing longitudinal aberration of the imaging lens according to Example 5 during focusing at a short distance; FIG. 11 is a lens cross-sectional view showing a sixth configuration example (Example 6) of an imaging lens according to an embodiment; FIG. 12 is an aberration diagram showing longitudinal aberration of the imaging lens according to Example 6 when focusing on infinity. FIG. 11 is an aberration diagram showing longitudinal aberration of the imaging lens according to Example 6 during focusing at a short distance. FIG. 11 is a lens cross-sectional view showing a seventh configuration example (Example 7) of an imaging lens according to an embodiment; FIG. 12 is an aberration diagram showing longitudinal aberration of the imaging lens according to Example 7 when focusing on infinity. FIG. 12 is an aberration diagram showing longitudinal aberration of the imaging lens according to Example 7 during focusing at a short distance. FIG. 11 is a lens cross-sectional view showing an eighth configuration example (Example 8) of an imaging lens according to an embodiment; FIG. 12 is an aberration diagram showing longitudinal aberration of the imaging lens according to Example 8 when focusing on infinity. FIG. 12 is an aberration diagram showing longitudinal aberration of the imaging lens according to Example 8 during focusing at a short distance. FIG. 20 is a lens cross-sectional view showing a ninth configuration example (Example 9) of an imaging lens according to an embodiment; FIG. 20 is an aberration diagram showing longitudinal aberration of the imaging lens according to Example 9 when focusing on infinity. FIG. 20 is an aberration diagram showing longitudinal aberration of the imaging lens according to Example 9 during focusing at a short distance. It is a block diagram which shows one structural example of an imaging device. 1 is a block diagram showing an example of a schematic configuration of a vehicle control system; FIG. FIG. 4 is an explanatory diagram showing an example of installation positions of an outside information detection unit and an imaging unit; 1 is a configuration diagram showing an example of a schematic configuration of an endoscopic surgery system; FIG. 32 is a block diagram showing an example of the functional configuration of the camera head and CCU shown in FIG. 31; FIG.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be given in the following order.
0. Comparative example 1. Basic configuration of lens 2 . Action and effect 3. Example of application to imaging device 4. Numerical Examples of Lenses 5 . Application example 6 . Other embodiments

<0. Comparative example>
The technology described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2018-205527) provides a large-aperture wide-angle single-focal lens, but the number of lenses increases in order to correct various aberrations that occur with the increase in aperture. , lengthening. In addition, since the lens closest to the object side is a convex lens, the diameter of the lens becomes large, making it difficult to reduce the size of the optical system.

Further, the technology described in Patent Document 2 (International Publication No. 2017/168603) provides a wide-angle lens with a large aperture, but the lateral magnification of the focusing group and the fixed group located closer to the image plane than the focusing group The relationship with the lateral magnification is not optimal, and the angle of view fluctuates greatly during focusing.

<1. Basic Configuration of Lens>
An embodiment of the present disclosure relates to a single-focus lens suitable for a digital still camera, a digital mirrorless camera, and the like, and an optical device having the single-focus lens. In particular, the present invention relates to a compact, high-performance imaging lens that uses a focusing method capable of performing good aberration correction, and an imaging apparatus equipped with such an imaging lens.

FIG. 1 shows a first configuration example of an imaging lens according to an embodiment of the present disclosure, which corresponds to the configuration of Example 1 described later. FIG. 4 shows a second configuration example of the imaging lens according to one embodiment, which corresponds to the configuration of Example 2 described later. FIG. 7 shows a third configuration example of an imaging lens according to one embodiment, which corresponds to the configuration of Example 3 described later. FIG. 10 shows a fourth configuration example of an imaging lens according to an embodiment, which corresponds to the configuration of Example 4 described later. FIG. 13 shows a fifth configuration example of the imaging lens according to one embodiment, which corresponds to the configuration of Example 5 described later. FIG. 16 shows a sixth configuration example of an imaging lens according to an embodiment, which corresponds to the configuration of Example 6 described later. FIG. 19 shows a seventh configuration example of an imaging lens according to one embodiment, which corresponds to the configuration of Example 7 described later. FIG. 22 shows an eighth configuration example of an imaging lens according to one embodiment, which corresponds to the configuration of Example 8 described later. FIG. 25 shows a ninth configuration example of an imaging lens according to an embodiment, which corresponds to the configuration of Example 9 described later.

In FIG. 1 and the like, Z1 indicates the optical axis. An optical member FL such as a cover glass for protecting the image sensor may be arranged between the imaging lenses 1 to 9 and the image plane according to the first to ninth configuration examples. In addition to the cover glass, various optical filters such as a low-pass filter and an infrared cut filter may be arranged as the optical member FL.

Hereinafter, the configuration of an imaging lens according to an embodiment of the present disclosure will be described in association with the imaging lenses 1 to 9 according to each configuration example shown in FIG. It is not limited to the configuration example. Also, hereinafter, a configuration example of a first imaging lens according to an embodiment and a second imaging lens according to an embodiment will be described as imaging lenses according to an embodiment of the present disclosure.

(Basic Configuration of First Imaging Lens According to One Embodiment)
The first imaging lens according to one embodiment comprises, in order from the object side to the image plane side, a first lens group G1 having at least two negative lenses and a second lens group G2 having positive refractive power. and a third lens group G3 having negative refractive power. In the first imaging lens according to one embodiment, when the subject distance changes from infinity to short, the first lens group G1 is fixed, and the second lens group G2 or the second lens group G2 and the third lens group G2 are fixed. Focusing is performed by moving the lens group G3 in the optical axis direction.

In Examples 1 to 7 and Example 9, which will be described later, the second lens group G2 is used as the focus group. In Example 8, the second lens group G2 and the third lens group G3 are used as the focus group. FIG. 1 and the like show the lens arrangement during focusing at infinity. In FIG. 1 and the like, arrows indicate the moving direction of the focus group when focusing from infinity to a short distance.

A first imaging lens according to an embodiment satisfies the following conditional expressions (1), (2), and (3).
-1.05<f2/f3<-0.25 (1)
1.38<β3 (2)
0.2<(R11-R12)/(R11+R12)<0.8 (3)
however,
f2: focal length of the second lens group G2 f3: focal length of the third lens group G3 β3: lateral magnification of the third lens group G3 R1: radius of curvature of the object-side surface of the lens closest to the object R2: closest to the object is the radius of curvature of the image-side surface of the lens.

In addition, the first imaging lens according to one embodiment may further satisfy predetermined conditional expressions and the like to be described later.

In Examples described later, Examples 1 to 9 satisfy the configuration of the first imaging lens according to the embodiment.

(Basic Configuration of Second Imaging Lens According to One Embodiment)
The second imaging lens according to one embodiment comprises, in order from the object side to the image plane side, a first lens group G1 having at least two negative lenses and a second lens group G2 having positive refractive power. and a third lens group G3 having negative refractive power. In the second imaging lens according to one embodiment, the first lens group G1 consists of a 1a lens group G1a, an aperture stop St, and a 1b lens group G1b in order from the object side to the image plane side. The second lens group G2 consists of at least one positive lens and at least one negative lens. In the second imaging lens according to one embodiment, when the subject distance changes from infinity to short, the first lens group G1 is fixed, and the second lens group G2 or the second lens group G2 and the third lens group G2 are fixed. Focusing is performed by moving the lens group G3 in the optical axis direction.

A second imaging lens according to an embodiment satisfies the following conditional expressions (1) and (9).
-1.05<f2/f3<-0.25 (1)
|β2|<0.45 (9)
however,
f2: focal length of the second lens group G2 f3: focal length of the third lens group G3 β2: lateral magnification of the second lens group G2.

In Examples described later, Examples 1, 2, and 4 to 8 satisfy the configuration of the second imaging lens according to one embodiment.

In addition, the second imaging lens according to one embodiment may further satisfy predetermined conditional expressions and the like to be described later.

<2. Action/Effect>
Next, the action and effect of the imaging lens according to the embodiment of the present disclosure will be described. In addition, a more preferable configuration of the imaging lens according to the embodiment of the present disclosure, and its actions and effects will be described.
Note that the effects described in this specification are merely examples and are not limited, and other effects may also occur.

According to the imaging lens according to the embodiment, in the configuration consisting of the first lens group G1 to the third lens group G3, it has high optical performance while being compact and large in diameter, and the angle of view fluctuation during focusing is minimized. The power of the lens group and the lateral magnification are optimized so that this can be suppressed. As a result, it is possible to provide an imaging lens and an imaging apparatus that are small in size and have a large aperture, yet have high optical performance, and in which fluctuations in the angle of view during focusing are suppressed.

(Action and effect of the first imaging lens according to one embodiment)
In the first imaging lens according to one embodiment, the first lens group G1 plays a role of a wide converter that secures a sufficient back focus while enlarging the angle of view in the entire optical system. The configuration of the second lens group G2 and the third lens group G3 is of a telephoto type, which contributes to miniaturization. In the first imaging lens according to one embodiment, the first lens group G1 has two or more negative lenses, and various aberrations such as coma and field curvature are corrected by dividing the negative refractive power. It is possible to

Conditional expression (1) defines the ratio of the focal length of the second lens group G2 to the focal length of the third lens group G3 within a preferable range in order to achieve miniaturization and high performance of the optical system. is. When the upper limit of conditional expression (1) is exceeded, the focal length of the second lens group G2 becomes short, and the total optical length becomes short. It becomes difficult to secure On the other hand, when the lower limit of conditional expression (1) is not reached, the focal length of the second lens group G2 becomes longer, and the power to converge light rays becomes weaker. .

From the viewpoint of improving the performance of the optical system, the upper limit of conditional expression (1) may be -0.30.

The conditional expression (2) defines a preferable range of the lateral magnification of the third lens group G3 in order to suppress variation in the angle of view during focusing while ensuring focus sensitivity. If the lower limit of conditional expression (2) is not reached, the lateral magnification of the second lens group G2 increases in order to ensure focus sensitivity, making it difficult to suppress variations in the angle of view during focusing.

As the value of conditional expression (2) increases, the refractive power of the third lens group G3 increases, making it difficult to correct various aberrations and to ensure a good optical system. From the viewpoint of improving the performance of the optical system, the following conditional expression (2A), which further sets the upper limit to the conditional expression (2), may be satisfied.
1.38<β3<2.0 (2A)

Conditional expression (3) defines the shape of the lens closest to the object within a preferable range for achieving high performance of the optical system. If the upper limit of conditional expression (3) is exceeded, the refractive power of the lens closest to the object side will become strong, making it difficult to correct various aberrations such as coma, astigmatism, and curvature of field. On the other hand, when the lower limit of conditional expression (3) is not reached, the refractive power of the lens closest to the object becomes weak, and the angle of refraction with respect to the incident light becomes small, making it difficult to secure the angle of view.

From the viewpoint of correction of various aberrations, the upper limit of conditional expression (3) may be set to 0.65. Also, from the viewpoint of miniaturization of the optical system, the lower limit of conditional expression (3) may be set to 0.28.

Moreover, the first imaging lens according to one embodiment may satisfy the following conditional expression (4).
1.0<f2/f<2.1 (4)
however,
f: The focal length of the entire system when focused to infinity.

Conditional expression (4) defines the ratio between the focal length of the second lens group G2 and the focal length of the entire system within a preferable range. The second lens group G2 plays a role of converging light rays in the entire optical system. If the upper limit of conditional expression (4) is exceeded, the focal length of the second lens group G2 becomes longer, and the ability to converge light rays becomes weaker. Become. If the lower limit of conditional expression (4) is not reached, the focal length of the second lens group G2 becomes longer and the power to converge light rays becomes stronger. Various aberrations caused by the lens cannot be corrected, and it becomes difficult to ensure good performance.

From the viewpoint of miniaturization of the optical system, the upper limit of conditional expression (4) may be set to 1.9. Also, from the viewpoint of improving the performance of the optical system, the lower limit of conditional expression (4) may be set to 1.1.

Also, the first imaging lens according to one embodiment may satisfy the following conditional expression (5).
0.5<f2_Llast/f2<4.5 (5)
however,
f2_Llast: The focal length of the lens closest to the image plane in the second lens group G2.

Conditional expression (5) defines the ratio between the focal length of the lens closest to the image plane in the second lens group G2 and the focal length of the second lens group G2 within a preferable range. The lens closest to the image plane in the second lens group G2 plays a role of converging the axial light flux and moderating the angle of incidence of the peripheral light flux on the image sensor. If the upper limit of conditional expression (5) is exceeded, the refractive power of the peripheral light flux by the lens closest to the image plane in the second lens group G2 will weaken, and the angle of incidence on the image sensor will increase. As a result, it becomes difficult to ensure both the amount of peripheral light and the correction of various aberrations such as coma. If the lower limit of conditional expression (5) is not reached, the refractive power of the lens closest to the object side in the second lens group G2 becomes strong, making it difficult to correct various aberrations generated in the lens closest to the object side in the second lens group G2. This makes it difficult to ensure good performance.

Note that the upper limit value of conditional expression (5) may be set to 4.1 from the viewpoint of securing the peripheral light amount of the optical system. Also, from the viewpoint of improving the performance of the optical system, the lower limit of conditional expression (5) may be set to 0.65.

Also, the first imaging lens according to one embodiment may satisfy the following conditional expression (6).
1.0<|K2|<3.5 (6)
however,
K2: Focus sensitivity of the second lens group G2 when focused to infinity K2=|(β3 ² )×(1−β2 ² )|
β2: Lateral magnification of the second lens group G2 β3: Lateral magnification of the third lens group G3.

Conditional expression (6) defines the focus sensitivity of the second lens group G2 within a preferable range. If the upper limit of conditional expression (6) is exceeded, the refractive powers of the second lens group G2 and the third lens group G3 will increase, making it difficult to correct various aberrations. If the lower limit of conditional expression (6) is not reached, the amount of movement of the second lens group G2 during focusing increases, making it difficult to reduce the size of the optical system.

From the viewpoint of improving the performance of the optical system, the upper limit of conditional expression (6) may be set to 3.0. Also, from the viewpoint of miniaturization of the optical system, the lower limit of conditional expression (6) may be set to 1.5.

Further, in the first imaging lens according to one embodiment, the optical distance on the optical axis from the lens surface on the image plane side of the lens closest to the image plane in the optical system to the image plane is the back focus BF. In this case, the relationship between the focal length f of the entire system and the back focus BF may satisfy the following conditions. When a parallel plate-shaped optical element such as a cover glass or a filter is interposed between the image plane side lens surface of the lens closest to the image plane and the image plane, the definition of the back focus BF is the closest to the image plane side. is the air conversion distance from the lens surface on the image side of the lens to the image surface.
The following conditional expression (7) may be satisfied.
0.3<BF/f<2.5 (7)
however,
f: focal length of the entire system when focused to infinity BF: distance from the lens surface closest to the image plane to the image plane.

The conditional expression (7) defines the ratio between the back focus BF and the focal length f of the entire system within a preferable range. If the upper limit of conditional expression (7) is exceeded, the back focus BF becomes long, making it difficult to shorten the overall length. On the other hand, when the lower limit is not reached, it becomes difficult to properly secure the back focus BF, and manufacturability deteriorates.

By setting the upper limit of conditional expression (7) to 1.55, the back focus BF can be shortened and the overall length can be further shortened. Further, by setting the lower limit of conditional expression (7) to 0.4, the back focus BF can be secured more appropriately, so that productivity can be further improved.

The first imaging lens according to one embodiment may have an aperture stop closer to the object side than the second lens group G2. This makes it possible to suppress various aberrations occurring in the first lens group G1.

Moreover, the first imaging lens according to one embodiment may satisfy the following conditional expression (8).
1.5<nL1<2.2 (8)
however,
nL1: The refractive index of the lens closest to the object side.

The conditional expression (8) defines the refractive index of the lens closest to the object within a preferable range. If the lower limit of conditional expression (8) is not reached, the refractive power of the lens closest to the object becomes weak and the diameter of the lens closest to the object increases, making it difficult to reduce the size of the optical system. If the upper limit of conditional expression (8) is exceeded, it will be difficult to reduce the weight of the optical system because the high refractive index glass material generally has a high specific gravity.

By setting the upper limit of conditional expression (8) to 2.1, the optical system can be made lighter and have higher performance. By setting the lower limit of conditional expression (8) to 1.55, the diameter of the lens closest to the object side can be made smaller, and the optical system can be made more compact.

In addition, the first imaging lens according to one embodiment may be configured to have at least ten lenses as a whole of the first lens group G1, the second lens group G2, and the third lens group G3. . In the first imaging lens according to one embodiment, it is preferable to satisfactorily correct various aberrations in order to provide a large-aperture, high-performance optical system. becomes difficult.

(Action and effect of the second imaging lens according to one embodiment)
In the second imaging lens according to one embodiment, the first lens group G1 plays a role of a wide converter that secures a sufficient back focus while enlarging the angle of view in the entire optical system. The configuration of the second lens group G2 and the third lens group G3 is of a telephoto type, which contributes to miniaturization. In the second imaging lens according to one embodiment, the first lens group G1 is composed of the 1a lens group G1a, the aperture diaphragm St, and the 1b lens group G1b in order from the object side. Since the upper and lower rays can be appropriately corrected within the group G1, it is possible to suppress various aberrations occurring within the first lens group G1. In addition, in the second imaging lens according to one embodiment, the first lens group G1 has two or more negative lenses, and by dividing the negative refractive power, various aberrations such as coma and curvature of field are corrected. can be corrected. In addition, in the second imaging lens according to the embodiment, the second lens group G2 has at least one positive lens and at least one negative lens, so that Occurrence of various aberrations can be suppressed, and aberration fluctuations during focusing can be suppressed.

Conditional expression (9) above defines a preferable range of the lateral magnification of the second lens group G2 in order to suppress variation in the angle of view during focusing. If the upper limit of conditional expression (9) is exceeded, the lateral magnification of the second lens group G2 will increase, and magnification fluctuation during focusing will increase, making it difficult to suppress the angle of view fluctuation rate during focusing.

Further, in the second imaging lens according to one embodiment, at least one of the conditional expressions (5) to (8) may be satisfied. The actions and effects obtained by satisfying the conditional expressions (5) to (8) are the same as those of the first imaging lens according to the embodiment.

In addition, the second imaging lens according to one embodiment may be configured to have at least 11 lenses as a whole of the first lens group G1, the second lens group G2, and the third lens group G3. . In the second imaging lens according to one embodiment, it is preferable to satisfactorily correct various aberrations in order to provide a large-aperture, high-performance optical system. becomes difficult.

<3. Example of application to imaging device>
Next, a specific application example of the imaging lens according to the embodiment of the present disclosure to an imaging apparatus will be described.

FIG. 28 shows a configuration example of an imaging device 100 to which an imaging lens according to one embodiment is applied. This imaging device 100 is, for example, a digital still camera, and includes a camera block 10, a camera signal processing section 20, an image processing section 30, an LCD (Liquid Crystal Display) 40, and a R/W (reader/writer) 50. , a CPU (Central Processing Unit) 60 , an input section 70 , and a lens driving control section 80 .

The camera block 10 has an imaging function, and has an imaging lens 11 and an imaging element 12 such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). The imaging device 12 converts an optical image formed by the imaging lens 11 into an electrical signal, and outputs an imaging signal (image signal) corresponding to the optical image. As the imaging lens 11, the imaging lenses 1 to 9 according to the configuration examples shown in FIG. 1 and the like can be applied.

The camera signal processing unit 20 performs various signal processing such as analog-to-digital conversion, noise removal, image quality correction, and conversion to luminance/color difference signals on the image signal output from the imaging device 12 .

The image processing unit 30 performs recording and reproduction processing of image signals, and performs compression encoding/expansion decoding processing of image signals based on a predetermined image data format, conversion processing of data specifications such as resolution, and the like. It's becoming

The LCD 40 has a function of displaying various data such as the operation state of the user's input unit 70 and captured images. The R/W 50 writes image data encoded by the image processing unit 30 to the memory card 1000 and reads image data recorded on the memory card 1000 . The memory card 1000 is, for example, a semiconductor memory that can be inserted into and removed from a slot connected to the R/W 50 .

The CPU 60 functions as a control processing section that controls each circuit block provided in the imaging apparatus 100 and controls each circuit block based on an instruction input signal or the like from the input section 70 . The input unit 70 includes various switches and the like that are operated by the user. The input unit 70 includes, for example, a shutter release button for operating the shutter, a selection switch for selecting an operation mode, and the like, and outputs an instruction input signal to the CPU 60 according to the user's operation. ing. The lens drive control unit 80 controls driving of the lenses arranged in the camera block 10, and controls motors (not shown) that drive the lenses of the imaging lens 11 based on control signals from the CPU 60. It's becoming

The operation of the imaging device 100 will be described below.
In the standby state for photographing, under the control of the CPU 60, an image signal photographed by the camera block 10 is output to the LCD 40 via the camera signal processing section 20 and displayed as a camera-through image. Further, for example, when an instruction input signal for zooming or focusing is input from the input unit 70, the CPU 60 outputs a control signal to the lens drive control unit 80, and the image pickup lens 11 is adjusted based on the control of the lens drive control unit 80. is moved.

When the shutter (not shown) of the camera block 10 is operated by an instruction input signal from the input unit 70, the photographed image signal is output from the camera signal processing unit 20 to the image processing unit 30, where it is compression-encoded and processed by a predetermined Converted to digital data in data format. The converted data is output to the R/W 50 and written to the memory card 1000. FIG.

Focusing is performed by the lens drive control unit 80 based on a control signal from the CPU 60 when, for example, the shutter release button of the input unit 70 is half-pressed or fully-pressed for recording (photographing). This is performed by moving a predetermined lens of the imaging lens 11 .

When reproducing image data recorded on the memory card 1000, predetermined image data is read from the memory card 1000 by the R/W 50 in response to an operation on the input unit 70, and decompressed and decoded by the image processing unit 30. After processing, the reproduced image signal is output to the LCD 40 to display the reproduced image.

In the above-described embodiment, an example in which the imaging device is applied to a digital still camera or the like is shown, but the scope of application of the imaging device is not limited to the digital still camera, and can be applied to various other imaging devices. It is possible. For example, it can be applied to digital single-lens reflex cameras, digital non-reflex cameras, digital video cameras, surveillance cameras, and the like. Further, it can be widely applied as a camera unit of a digital input/output device such as a mobile phone with a built-in camera or an information terminal with a built-in camera. It can also be applied to a camera with interchangeable lenses.

<4. Numerical Examples of Lenses>
Next, specific numerical examples of the imaging lens according to the embodiment of the present disclosure will be described. Here, an example in which specific numerical values are applied to the imaging lenses 1 to 9 according to each configuration example shown in FIG. 1 and the like will be described.

Note that the meanings of the symbols shown in the tables and explanations below are as follows. "Si" indicates the number of the i-th surface, which is numbered sequentially from the object side. “ri” indicates the value (mm) of the paraxial radius of curvature of the i-th surface. "di" indicates the distance (mm) on the optical axis between the i-th surface and the (i+1)-th surface. "ndi" indicates the refractive index value for the d-line (wavelength 587.6 nm) of the material of the optical element having the i-th surface. "νdi" indicates the value of the Abbe number at the d-line of the material of the optical element having the i-th surface. A portion where the value of "ri" is "∞" indicates a flat surface, an aperture surface, or the like. "ASP" in the surface number (Si) column indicates that the surface is configured in an aspherical shape. "STO" in the surface number column indicates that the aperture stop St is arranged at the corresponding position. "OBJ" in the plane number column indicates that the plane is an object plane (object plane). "IMG" in the surface number column indicates that the surface is the image surface. "f" indicates the focal length of the entire system (unit: mm). "Fno" indicates the open F value (F number). "ω" indicates a half angle of view (unit: °). "Y" indicates image height (unit: mm). "L" indicates the total optical length (distance on the optical axis from the surface closest to the object to the image plane IMG) (unit: mm).

Moreover, some of the lenses used in each embodiment have an aspherical lens surface. An aspheric shape is defined by the following equation. In each table showing aspheric coefficients described later, "Ei" represents an exponential expression with the base of 10, that is, "10 ^-i ". For example, "0.12345E-05" is " 0.12345×10 ⁻⁵ ″.

(formula for aspheric surface)
x=cy ² /(1+(1−(1+k)c ² y ² ) ^1/2 )+A4·y ⁴ +A6·y ⁶ +A8·y ⁸ +A10·y ¹⁰ +A12·y ¹²
Here, the distance (sag amount) in the direction of the optical axis from the vertex of the lens surface is "x", the height in the direction perpendicular to the optical axis is "y", and the paraxial curvature at the vertex of the lens surface (reciprocal of the radius of curvature ) is “c” and the conic constant is “k”. A4, A6, A8, A10 and A12 are the 4th, 6th, 8th, 10th and 12th aspheric coefficients, respectively.

[Example 1]
[Table 1] shows basic lens data of the imaging lens 1 according to Example 1 shown in FIG. [Table 2] shows values of the focal length f, F value, total angle of view 2ω, image height Y, and optical total length L of the imaging lens 1 according to Example 1. [Table 3] shows the data of the surface distance that becomes variable during focusing in the imaging lens 1 according to the first embodiment. [Table 4] shows the values of the coefficients representing the shape of the aspheric surface in the imaging lens 1 according to Example 1. [Table 5] shows the starting surface and the focal length (unit: mm) of each lens group of the imaging lens 1 according to the first embodiment.

The imaging lens 1 according to Example 1 includes, in order from the object side toward the image plane, a first lens group G1 having positive refractive power, a second lens group G2 having positive refractive power, and a negative refractive power. and a third lens group G3 having

The first lens group G1 is composed of, in order from the object side to the image plane side, a 1a-th lens group G1a, an aperture diaphragm St, and a 1b-th lens group G1b. The 1a-th lens group G1a is composed of lenses L1 to L7. The 1b-th lens group G1b consists of a lens L8. The lens L1 is a negative meniscus lens with a convex surface facing the object side. Lens L2 is a negative meniscus lens with a convex surface facing the object side. Lens L3 is a bilaterally concave negative lens. The lens L4 is a biconvex positive lens. Lens L5 is a bilaterally concave negative lens. The lens L6 is a biconvex positive lens. The lens L7 is a biconvex positive lens. The lens L8 is a biconvex positive lens. The lens L3 is an aspherical lens having aspherical shapes formed on both sides. Lens L5 and lens L6 are bonded together to form a cemented lens.

As described above, the first lens group G1 is composed of eight lenses. Assuming that the cemented lens is one lens component, the first lens group G1 is composed of seven lens components.

The second lens group G2 is composed of three lenses L9 to L11 in order from the object side to the image plane side. Lens L9 is a bilaterally concave negative lens. The lens L10 is a biconvex positive lens. The lens L11 is a biconvex positive lens. The lens L9 is an aspherical lens having aspherical surfaces formed on both sides.

The third lens group G3 is composed of one lens L12. The lens L12 is a negative lens with concave surfaces on both sides.

In the imaging lens 1 according to Example 1, when the subject distance changes from infinity to short, the first lens group G1 is fixed, and the distance between the lens L8 and the lens L9 and the distance between the lens L11 and the lens L12 are fixed. Focusing is performed by changing the spacing and moving the second lens group G2 in the optical axis direction.

FIG. 2 shows the longitudinal aberration of the imaging lens 1 according to Example 1 during focusing at infinity. FIG. 3 shows the longitudinal aberration of the imaging lens 1 according to Example 1 at the time of short-distance focusing.

2 and 3 show spherical aberration, astigmatism (curvature of field), and distortion as longitudinal aberrations. In the spherical aberration diagrams of FIGS. 2 and 3, the solid line indicates the d-line (587.56 nm), the dashed line indicates the g-line (435.84 nm), and the dashed line indicates the C-line (656.27 nm). In the astigmatism diagrams, S indicates the value on the sagittal image plane, and T indicates the value on the tangential image plane. The distortion diagrams show the values at the d-line.
The same applies to aberration diagrams in other examples below.

The imaging lens 1 according to Example 1 achieves size reduction while realizing a large aperture of about F number 1.4 by the above configuration. Further, as can be seen from each aberration diagram, the imaging lens 1 according to Example 1 has various aberrations well corrected and has excellent imaging performance.

[Example 2]
[Table 6] shows basic lens data of the imaging lens 2 according to Example 2 shown in FIG. [Table 7] shows values of the focal length f of the entire system, the F value, the total angle of view 2ω, the image height Y, and the total optical length L of the imaging lens 2 according to Example 2. [Table 8] shows the data of the surface spacing that becomes variable during focusing in the imaging lens 2 according to the second embodiment. [Table 9] shows the values of the coefficients representing the shape of the aspheric surface in the imaging lens 2 according to Example 2. [Table 10] shows the starting surface and the focal length (unit: mm) of each lens group of the imaging lens 2 according to the second embodiment.

The imaging lens 2 according to Example 2 includes, in order from the object side toward the image plane, a first lens group G1 having positive refractive power, a second lens group G2 having positive refractive power, and a negative refractive power. and a third lens group G3 having

The first lens group G1 comprises, in order from the object side to the image plane side, a 1a-th lens group G1a, an aperture stop St, and a 1b-th lens group G1b. The 1a-th lens group G1a is composed of lenses L1 to L4. The 1b-th lens group G1b consists of lenses L5 and L6. The lens L1 is a negative meniscus lens with a convex surface facing the object side. Lens L2 is a negative meniscus lens with a convex surface facing the object side. The lens L3 is a biconvex positive lens. The lens L4 is a negative meniscus lens with a convex surface facing the image side. The lens L5 is a biconvex positive lens. Lens L6 is a negative meniscus lens with a convex surface facing the object side. The lens L4 is an aspherical lens having aspherical shapes formed on both sides.

As described above, the first lens group G1 is composed of six lenses.

The second lens group G2 is composed of four lenses L7 to L10 in order from the object side to the image plane side. The lens L7 is a biconvex positive lens. Lens L8 is a bilaterally concave negative lens. The lens L9 is a biconvex positive lens. The lens L10 is a biconvex positive lens. Lens L7 and lens L8 are bonded together to form a cemented lens. The lens L9 is an aspherical lens having aspherical surfaces formed on both sides.

As described above, the second lens group G2 is composed of four lenses. Assuming that the cemented lens is one lens component, the second lens group G2 is composed of three lens components.

The third lens group G3 is composed of one lens L11. The lens L11 is a negative meniscus lens with a convex surface facing the object side.

In the imaging lens 2 according to Example 2, when the subject distance changes from infinity to short, the first lens group G1 is fixed, and the distance between the lens L6 and the lens L7 and the distance between the lens L10 and the lens L11 are fixed. Focusing is performed by changing the spacing and moving the second lens group G2 in the optical axis direction.

FIG. 5 shows the longitudinal aberration of the imaging lens 2 according to Example 2 during focusing at infinity. FIG. 6 shows the longitudinal aberration of the imaging lens 2 according to Example 2 at the time of short-distance focusing.

The imaging lens 2 according to Example 2 achieves a small size while realizing a large aperture of about F number 1.8 by the above configuration. Further, as can be seen from each aberration diagram, the imaging lens 2 according to Example 2 has various aberrations well corrected and has excellent imaging performance.

[Example 3]
[Table 11] shows basic lens data of the imaging lens 3 according to Example 3 shown in FIG. [Table 12] shows values of the focal length f of the entire system, the F value, the total angle of view 2ω, the image height Y, and the total optical length L of the imaging lens 3 according to Example 3. [Table 13] shows the data of the surface distance that becomes variable during focusing in the imaging lens 3 according to the third embodiment. [Table 14] shows the values of the coefficients representing the shape of the aspheric surface in the imaging lens 3 according to Example 3. [Table 15] shows the starting surface and focal length (unit: mm) of each lens group of the imaging lens 3 according to Example 3.

The imaging lens 3 according to Example 3 includes, in order from the object side toward the image plane, a first lens group G1 having positive refractive power, an aperture stop St, and a second lens group G2 having positive refractive power. , and a third lens group G3 having negative refractive power.

The first lens group G1 is composed of five lenses L1 to L5 in order from the object side to the image plane side. The lens L1 is a negative meniscus lens with a convex surface facing the object side. The lens L2 is a bilaterally concave negative lens. The lens L3 is a biconvex positive lens. The lens L4 is a bilaterally concave negative lens. The lens L5 is a biconvex positive lens.

The second lens group G2 is composed of four lenses L6 to L9 in order from the object side to the image plane side. The lens L6 is a negative meniscus lens with a convex surface facing the image side. The lens L7 is a biconvex positive lens. Lens L8 is a negative meniscus lens with a convex surface facing the image side. The lens L9 is a biconvex positive lens L9. The lens L6 is a composite lens integrated with resin having an aspherical shape. Lens L7 and lens L8 are bonded together to form a cemented lens. The lens L9 is an aspherical lens having aspherical surfaces formed on both sides.

As described above, the second lens group G2 is composed of four lenses. Assuming that the cemented lens is one lens component, the second lens group G2 is composed of three lens components.

The third lens group G3 is composed of one lens L10. The lens L10 is a bilaterally concave negative lens.

In the imaging lens 3 according to Example 3, when the subject distance changes from infinity to short, the first lens group G1 is fixed, and the distance between the lens L5 and the lens L6 and the distance between the lens L9 and the lens L10 are fixed. Focusing is performed by changing the spacing and moving the second lens group G2 in the optical axis direction.

FIG. 8 shows the longitudinal aberration of the imaging lens 3 according to Example 3 during focusing at infinity. FIG. 9 shows the longitudinal aberration of the imaging lens 3 according to Example 3 at the time of short-distance focusing.

The imaging lens 3 according to Example 3 achieves size reduction while realizing a large aperture of about F number 1.8 by the above configuration. Further, as can be seen from each aberration diagram, the imaging lens 3 according to Example 3 has various aberrations well corrected and has excellent imaging performance.

[Example 4]
[Table 16] shows basic lens data of the imaging lens 4 according to Example 4 shown in FIG. [Table 17] shows values of the focal length f of the entire system, the F value, the total angle of view 2ω, the image height Y, and the total optical length L of the imaging lens 4 according to Example 4. [Table 18] shows the data of the surface spacing that becomes variable during focusing in the imaging lens 4 according to the fourth embodiment. [Table 19] shows the values of the coefficients representing the shape of the aspheric surface in the imaging lens 4 according to Example 4. [Table 20] shows the starting surface and the focal length (unit: mm) of each lens group of the imaging lens 4 according to the fourth embodiment.

The imaging lens 4 according to Example 4 includes, in order from the object side toward the image plane, a first lens group G1 having positive refractive power, a second lens group G2 having positive refractive power, and a negative refractive power. and a third lens group G3 having

The first lens group G1 is composed of, in order from the object side to the image plane side, a 1a-th lens group G1a, an aperture diaphragm St, and a 1b-th lens group G1b. The 1a-th lens group G1a is composed of lenses L1 to L5. The 1b-th lens group G1b consists of a lens L6. The lens L1 is a negative meniscus lens with a convex surface facing the object side. The lens L2 is a bilaterally concave negative lens. Lens L3 is a positive meniscus lens with a convex surface facing the object side. Lens L4 is a positive meniscus lens with a convex surface facing the object side. The lens L5 is a biconvex positive lens. The lens L6 is a positive meniscus lens with a convex surface facing the image side.

As described above, the first lens group G1 is composed of six lenses.

The second lens group G2 is composed of five lenses L7 to L11 in order from the object side to the image plane side. The lens L7 is a biconvex positive lens. Lens L8 is a bilaterally concave negative lens. The lens L9 is a biconvex positive lens. The lens L10 is a negative meniscus lens with a convex surface facing the object side. The lens L11 is a positive meniscus lens with a convex surface facing the image plane side. Lens L7 and lens L8 are bonded together to form a cemented lens. The lens L9 and the lens L10 are aspherical lenses having aspherical surfaces formed on both sides.

As described above, the second lens group G2 is composed of five lenses. Assuming that the cemented lens is one lens component, the second lens group G2 is composed of four lens components.

The third lens group G3 is composed of one lens L12. The lens L12 is a negative lens with concave surfaces on both sides.

In the imaging lens 4 according to Example 4, when the subject distance changes from infinity to short, the first lens group G1 is fixed, and the distance between the lens L6 and the lens L7 and the distance between the lens L11 and the lens L12 are fixed. Focusing is performed by changing the spacing and moving the second lens group G2 in the optical axis direction.

FIG. 11 shows the longitudinal aberration of the imaging lens 4 according to Example 4 during focusing at infinity. FIG. 12 shows the longitudinal aberration of the imaging lens 4 according to Example 4 at the time of short-distance focusing.

The imaging lens 4 according to Example 4 achieves a small size while achieving a large aperture of about F number 1.8 by the above configuration. Further, as can be seen from each aberration diagram, the imaging lens 4 according to Example 4 has various aberrations well corrected and has excellent imaging performance.

[Example 5]
[Table 21] shows basic lens data of the imaging lens 5 according to Example 5 shown in FIG. [Table 22] shows values of the focal length f, F value, total angle of view 2ω, image height Y, and total optical length L of the entire system in the imaging lens 5 according to Example 5. [Table 23] shows the data of the surface distance that becomes variable during focusing in the imaging lens 5 according to the fifth embodiment. [Table 24] shows the values of the coefficients representing the shape of the aspheric surface in the imaging lens 5 according to Example 5. [Table 25] shows the starting surface and the focal length (unit: mm) of each lens group of the imaging lens 5 according to Example 5.

The imaging lens 5 according to Example 5 includes, in order from the object side toward the image plane, a first lens group G1 having negative refractive power, a second lens group G2 having positive refractive power, and a negative refractive power. and a third lens group G3 having

The first lens group G1 is composed of, in order from the object side to the image plane side, a 1a-th lens group G1a, an aperture diaphragm St, and a 1b-th lens group G1b. The 1a-th lens group G1a is composed of lenses L1 to L5. The 1b-th lens group G1b consists of lenses L6 and L7. The lens L1 is a negative meniscus lens with a convex surface facing the object side. Lens L2 is a negative meniscus lens with a convex surface facing the object side. Lens L3 is a negative meniscus lens with a convex surface facing the object side. The lens L4 is a biconvex positive lens. The lens L5 is a negative meniscus lens with a convex surface facing the image side. The lens L6 is a biconvex positive lens. Lens L7 is a negative meniscus lens with a convex surface facing the object side. The lens L5 is an aspherical lens having aspherical shapes formed on both sides.

As described above, the first lens group G1 is composed of seven lenses.

The second lens group G2 is composed of four lenses L8 to L11 in order from the object side to the image plane side. The lens L8 is a biconvex positive lens. Lens L9 is a bilaterally concave negative lens. The lens L10 is a biconvex positive lens. The lens L11 is a biconvex positive lens. Lens L8 and lens L9 are glued together to form a cemented lens. The lens L10 is an aspherical lens having aspherical surfaces formed on both sides.

As described above, the second lens group G2 is composed of four lenses. Assuming that the cemented lens is one lens component, the second lens group G2 is composed of three lens components.

The third lens group G3 is composed of one lens L12. The lens L12 is a negative meniscus lens with a convex surface facing the object side.

In the imaging lens 5 according to Example 5, when the subject distance changes from infinity to short, the first lens group G1 is fixed, and the distance between the lens L7 and the lens L8 and the distance between the lens L11 and the lens L12 are fixed. Focusing is performed by changing the spacing and moving the second lens group G2 in the optical axis direction.

FIG. 14 shows the longitudinal aberration of the imaging lens 5 according to Example 5 during focusing at infinity. FIG. 15 shows the longitudinal aberration of the imaging lens 5 according to Example 5 at the time of short-distance focusing.

The imaging lens 5 according to Example 5 achieves size reduction while realizing a large aperture of about F number 1.8 by the above configuration. Further, as can be seen from each aberration diagram, the imaging lens 5 according to Example 5 has various aberrations well corrected and has excellent imaging performance.

[Example 6]
[Table 26] shows basic lens data of the imaging lens 6 according to Example 6 shown in FIG. [Table 27] shows values of the focal length f of the entire system, the F value, the total angle of view 2ω, the image height Y, and the total optical length L of the imaging lens 6 according to Example 6. [Table 28] shows the data of the surface spacing that becomes variable during focusing in the imaging lens 6 according to the sixth embodiment. [Table 29] shows the values of the coefficients representing the shape of the aspheric surface in the imaging lens 6 according to Example 6. [Table 30] shows the starting surface and the focal length (unit: mm) of each lens group of the imaging lens 6 according to Example 6.

The imaging lens 6 according to Example 6 includes, in order from the object side toward the image plane, a first lens group G1 having positive refractive power, a second lens group G2 having positive refractive power, and a negative refractive power. and a third lens group G3 having

The first lens group G1 comprises, in order from the object side to the image plane side, a 1a-th lens group G1a, an aperture stop St, and a 1b-th lens group G1b. The 1a-th lens group G1a is composed of lenses L1 to L7. The 1b-th lens group G1b consists of a lens L8. The lens L1 is a negative meniscus lens with a convex surface facing the object side. Lens L2 is a negative meniscus lens with a convex surface facing the object side. The lens L3 is a negative meniscus lens with a convex surface facing the image side. The lens L4 is a biconvex positive lens. The lens L5 is a negative meniscus lens with a convex surface facing the image side. The lens L6 is a positive meniscus lens with a convex surface facing the image side. Lens L7 is a positive meniscus lens with a convex surface facing the object side. The lens L8 is a biconvex positive lens L8. The lens L3 is an aspherical lens having aspherical shapes formed on both sides. Lens L5 and lens L6 are bonded together to form a cemented lens.

As described above, the first lens group G1 is composed of eight lenses. Assuming that the cemented lens is one lens component, the first lens group G1 is composed of seven lens components.

The second lens group G2 is composed of three lenses L9 to L11 in order from the object side to the image plane side. Lens L9 is a bilaterally concave negative lens. The lens L10 is a biconvex positive lens. The lens L11 is a biconvex positive lens. The lens L9 is an aspherical lens having aspherical surfaces formed on both sides.

The third lens group G3 is composed of one lens L12. The lens L12 is a negative lens with concave surfaces on both sides.

In the imaging lens 6 according to Example 6, when the subject distance changes from infinity to short, the first lens group G1 is fixed, and the distance between the lens L8 and the lens L9 and the distance between the lens L11 and the lens L12 are fixed. Focusing is performed by changing the spacing and moving the second lens group G2 in the optical axis direction.

FIG. 17 shows the longitudinal aberration of the imaging lens 6 according to Example 6 during focusing at infinity. FIG. 18 shows the longitudinal aberration of the imaging lens 7 according to Example 6 at the time of short-distance focusing.

The image pickup lens 6 according to Example 6 achieves a small size while realizing a large aperture of about F number 1.5 by the above configuration. Further, as can be seen from each aberration diagram, the imaging lens 6 according to Example 6 has various aberrations well corrected and has excellent imaging performance.

[Example 7]
[Table 31] shows basic lens data of the imaging lens 7 according to Example 7 shown in FIG. [Table 32] shows values of the focal length f of the entire system, the F value, the total angle of view 2ω, the image height Y, and the total optical length L of the imaging lens 7 according to Example 7. [Table 33] shows the data of the surface spacing that becomes variable during focusing in the imaging lens 7 according to the seventh embodiment. [Table 34] shows the values of the coefficients representing the shape of the aspheric surface in the imaging lens 7 according to Example 7. [Table 35] shows the starting surface and the focal length (unit: mm) of each lens group of the imaging lens 7 according to the seventh embodiment.

The imaging lens 7 according to Example 7 includes, in order from the object side toward the image plane, a first lens group G1 having positive refractive power, a second lens group G2 having positive refractive power, and a negative refractive power. and a third lens group G3 having

The first lens group G1 comprises, in order from the object side to the image plane side, a 1a-th lens group G1a, an aperture stop St, and a 1b-th lens group G1b. The 1a-th lens group G1a consists of lenses L1 to L6. The 1b-th lens group G1b consists of a lens L7. The lens L1 is a negative meniscus lens with a convex surface facing the object side. The lens L2 is a positive meniscus lens with a convex surface facing the image side. Lens L3 is a bilaterally concave negative lens. The lens L4 is a biconvex positive lens. Lens L5 is a positive meniscus lens with a convex surface facing the object side. The lens L6 is a positive meniscus lens with a convex surface facing the image side. The lens L7 is a positive meniscus lens with a convex surface facing the image side.

As described above, the first lens group G1 is composed of seven lenses.

The second lens group G2 is composed of four lenses L8 to L11 in order from the object side to the image plane side. Lens L8 is a bilaterally concave negative lens. The lens L9 is a biconvex positive lens. The lens L10 is a positive meniscus lens with a convex surface facing the image side. The lens L11 is a positive meniscus lens with a convex surface facing the image plane side. The lens L8 and the lens L10 are aspherical lenses having aspherical surfaces formed on both sides.

The third lens group G3 is composed of one lens L12. The lens L12 is a negative lens with concave surfaces on both sides.

In the imaging lens 7 according to Example 7, when the subject distance changes from infinity to short, the first lens group G1 is fixed, and the distance between the lens L7 and the lens L8 and the distance between the lens L11 and the lens L12 are fixed. Focusing is performed by changing the spacing and moving the second lens group G2 in the optical axis direction.

FIG. 20 shows the longitudinal aberration of the imaging lens 7 according to Example 7 during focusing at infinity. FIG. 21 shows the longitudinal aberration of the imaging lens 7 according to Example 7 at the time of short-distance focusing.

The image pickup lens 7 according to Example 7 achieves a small size while realizing a large aperture of about F number 1.8 by the above configuration. Further, as can be seen from each aberration diagram, the imaging lens 7 according to Example 7 has various aberrations well corrected and has excellent imaging performance.

[Example 8]
[Table 36] shows basic lens data of the imaging lens 8 according to Example 8 shown in FIG. [Table 37] shows the focal length f, F value, total angle of view 2ω, image height Y, and total optical length L of the imaging lens 8 according to Example 8. [Table 38] shows the data of the surface spacing that becomes variable during focusing in the imaging lens 8 according to Example 8. [Table 39] shows the values of the coefficients representing the shape of the aspheric surface in the imaging lens 8 according to Example 8. [Table 40] shows the starting surface and the focal length (unit: mm) of each lens group of the imaging lens 8 according to the eighth embodiment.

The imaging lens 8 according to Example 8 includes, in order from the object side toward the image plane, a first lens group G1 having positive refractive power, a second lens group G2 having positive refractive power, and a negative refractive power. and a third lens group G3 having

The first lens group G1 comprises, in order from the object side to the image plane side, a 1a-th lens group G1a, an aperture stop St, and a 1b-th lens group G1b. The 1a-th lens group G1a is composed of lenses L1 to L5. The 1b-th lens group G1b consists of a lens L6. The lens L1 is a negative meniscus lens with a convex surface facing the object side. The lens L2 is a bilaterally concave negative lens. The lens L3 is a biconvex positive lens. The lens L4 is a bilaterally concave negative lens. The lens L5 is a biconvex positive lens. The lens L6 is a positive meniscus lens with a convex surface facing the image side.

As described above, the first lens group G1 is composed of six lenses.

The second lens group G2 is composed of four lenses L7 to L10 in order from the object side to the image plane side. Lens L7 is a bilaterally concave negative lens. The lens L8 is a biconvex positive lens. The lens L9 is a negative meniscus lens with a convex surface facing the image side. The lens L10 is a biconvex positive lens. Lens L8 and lens L9 are glued together to form a cemented lens. The lens L7 and the lens L10 are aspherical lenses having aspherical surfaces formed on both sides.

As described above, the second lens group G2 is composed of four lenses. Assuming that the cemented lens is one lens component, the second lens group G2 is composed of three lens components.

The third lens group G3 is composed of one lens L11. The lens L11 is a negative meniscus lens with a convex surface facing the object side.

In the imaging lens 8 according to Example 8, when the object distance changes from infinity to short distance, the first lens group G1 is fixed, and the distance between the lens L6 and the lens L7 and the distance between the lens L10 and the lens L11 are fixed. , and the distance between the lens L11 and the image plane change, and the second lens group G2 and the third lens group G3 move in the optical axis direction, thereby performing focusing.

FIG. 23 shows the longitudinal aberration of the imaging lens 8 according to Example 8 during focusing at infinity. FIG. 24 shows the longitudinal aberration of the imaging lens 8 according to Example 8 when focusing at a short distance.

The imaging lens 8 according to Example 8 achieves a small size while realizing a large aperture of about F number 1.8 by the above configuration. Further, as can be seen from each aberration diagram, the imaging lens 8 according to Example 8 has various aberrations well corrected and has excellent imaging performance.

[Example 9]
[Table 41] shows basic lens data of the imaging lens 9 according to Example 9 shown in FIG. [Table 42] shows values of the focal length f of the entire system, the F value, the total angle of view 2ω, the image height Y, and the total optical length L of the imaging lens 9 according to Example 9. [Table 43] shows the data of the surface spacing that becomes variable during focusing in the imaging lens 9 according to the ninth embodiment. [Table 44] shows the values of the coefficients representing the shape of the aspheric surface in the imaging lens 9 according to Example 9. [Table 45] shows the starting surface and the focal length (unit: mm) of each lens group of the imaging lens 9 according to the ninth embodiment.

The imaging lens 9 according to Example 9 includes, in order from the object side toward the image plane, a first lens group G1 having negative refractive power, an aperture stop St, and a second lens group G2 having positive refractive power. , and a third lens group G3 having negative refractive power.

The first lens group G1 is composed of five lenses L1 to L5 in order from the object side to the image plane side. The lens L1 is a negative meniscus lens with a convex surface facing the object side. Lens L2 is a negative meniscus lens with a convex surface facing the object side. Lens L3 is a positive meniscus lens with a convex surface facing the object side. Lens L4 is a negative meniscus lens with a convex surface facing the object side. Lens L5 is a negative meniscus lens with a convex surface facing the object side. The lens L2 and the lens L5 are aspherical lenses having aspherical shapes formed on both sides.

The second lens group G2 is composed of four lenses L6 to L9 in order from the object side to the image plane side. The lens L6 is a positive meniscus lens with a convex surface facing the image side. The lens L7 is a negative meniscus lens with a convex surface facing the image side. The lens L8 is a biconvex positive lens. The lens L9 is a positive meniscus lens with a convex surface facing the image side. Lens L6 and lens L7 are bonded together to form a cemented lens. The lens L9 is an aspherical lens having aspherical surfaces formed on both sides.

As described above, the second lens group G2 is composed of four lenses. Assuming that the cemented lens is one lens component, the second lens group G2 is composed of three lens components.

The third lens group G3 is composed of one lens L10. The lens L10 is a bilaterally concave negative lens.

In the imaging lens 9 according to Example 9, when the subject distance changes from infinity to short, the first lens group G1 is fixed, and the distance between the lens L5 and the lens L6 and the distance between the lens L9 and the lens L10 are fixed. Focusing is performed by changing the spacing and moving the second lens group G2 in the optical axis direction.

FIG. 26 shows the longitudinal aberration of the imaging lens 9 according to Example 9 when focusing on infinity. FIG. 27 shows the longitudinal aberration of the imaging lens 9 according to Example 9 at the time of short-distance focusing.

The image pickup lens 9 according to Example 9 achieves a small size while realizing a large aperture of about F number 1.8 by the above configuration. Further, as can be seen from each aberration diagram, the imaging lens 9 according to Example 9 has various aberrations well corrected and has excellent imaging performance.

[Other Numerical Data of Each Example]
[Table 46] shows a summary of the values for each of the above conditional expressions for each example. As can be seen from [Table 46], for each conditional expression, the value of each example falls within the numerical range.

<5. Application example>
[5.1 First application example]
The technology according to the present disclosure can be applied to various products. For example, the technology according to the present disclosure can be applied to any type of movement, such as automobiles, electric vehicles, hybrid electric vehicles, motorcycles, bicycles, personal mobility, airplanes, drones, ships, robots, construction machinery, agricultural machinery (tractors), etc. It may also be implemented as a body-mounted device.

FIG. 29 is a block diagram showing a schematic configuration example of a vehicle control system 7000, which is an example of a mobile control system to which the technology according to the present disclosure can be applied. Vehicle control system 7000 comprises a plurality of electronic control units connected via communication network 7010 . In the example shown in FIG. 29, the vehicle control system 7000 includes a drive system control unit 7100, a body system control unit 7200, a battery control unit 7300, an outside information detection unit 7400, an inside information detection unit 7500, and an integrated control unit 7600. . A communication network 7010 connecting these plurality of control units conforms to any standard such as CAN (Controller Area Network), LIN (Local Interconnect Network), LAN (Local Area Network) or FlexRay (registered trademark). It may be an in-vehicle communication network.

Each control unit includes a microcomputer that performs arithmetic processing according to various programs, a storage unit that stores programs executed by the microcomputer or parameters used in various calculations, and a drive circuit that drives various devices to be controlled. Prepare. Each control unit has a network I/F for communicating with other control units via a communication network 7010, and communicates with devices or sensors inside and outside the vehicle by wired communication or wireless communication. A communication I/F for communication is provided. In FIG. 29, the functional configuration of the integrated control unit 7600 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 equipment I/F 7660, an audio image output unit 7670, An in-vehicle network I/F 7680 and storage unit 7690 are shown. Other control units are similarly provided with microcomputers, communication I/Fs, storage units, and the like.

Drive system control unit 7100 controls the operation of devices related to the drive system of the vehicle according to various programs. For example, the driving system control unit 7100 includes a driving force generator for generating driving force of the vehicle such as an internal combustion engine or a driving motor, a driving force transmission mechanism for transmitting the driving force to the wheels, and a steering angle of the vehicle. It functions as a control device such as a steering mechanism to adjust and a brake device to generate braking force of the vehicle. Drive system control unit 7100 may have a function as a control device such as ABS (Antilock Brake System) or ESC (Electronic Stability Control).

A vehicle state detection section 7110 is connected to the driving system control unit 7100 . The vehicle state detection unit 7110 includes, for example, a gyro sensor that detects the angular velocity of the axial rotational motion of the vehicle body, an acceleration sensor that detects the acceleration of the vehicle, an accelerator pedal operation amount, a brake pedal operation amount, and a steering wheel steering. At least one of sensors for detecting angle, engine speed or wheel rotation speed is included. Drive system control unit 7100 performs arithmetic processing using signals input from vehicle state detection unit 7110, and controls the internal combustion engine, drive motor, electric power steering device, brake device, and the like.

Body system control unit 7200 controls the operation of various devices mounted on the vehicle body according to various programs. For example, the body system control unit 7200 functions as a keyless entry system, a smart key system, a power window device, or a control device for various lamps such as headlamps, back lamps, brake lamps, winkers or fog lamps. In this case, body system control unit 7200 can receive radio waves transmitted from a portable device that substitutes for a key or signals from various switches. Body system control unit 7200 receives the input of these radio waves or signals and controls the door lock device, power window device, lamps, etc. of the vehicle.

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

External information detection unit 7400 detects information external to the vehicle in which vehicle control system 7000 is mounted. For example, at least one of the imaging section 7410 and the vehicle exterior information detection section 7420 is connected to the vehicle exterior information detection unit 7400 . The imaging unit 7410 includes at least one of a ToF (Time Of Flight) camera, a stereo camera, a monocular camera, an infrared camera, and other cameras. The vehicle exterior information detection unit 7420 includes, for example, an environment sensor for detecting the current weather or weather, or a sensor for detecting other vehicles, obstacles, pedestrians, etc. around the vehicle equipped with the vehicle control system 7000. ambient information detection sensor.

The environment sensor may be, for example, at least one of a raindrop sensor that detects rainy weather, a fog sensor that detects fog, a sunshine sensor that detects the degree of sunshine, and a snow sensor that detects snowfall. The ambient information detection sensor may be at least one of an ultrasonic sensor, a radar device, and a LIDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging) device. These imaging unit 7410 and vehicle exterior information detection unit 7420 may be provided as independent sensors or devices, or may be provided as a device in which a plurality of sensors or devices are integrated.

Here, FIG. 30 shows an example of installation positions of the imaging unit 7410 and the vehicle-exterior information detection unit 7420 . The imaging units 7910 , 7912 , 7914 , 7916 , and 7918 are provided, for example, at least one of the front nose, side mirrors, rear bumper, back door, and windshield of the vehicle 7900 . An image pickup unit 7910 provided in the front nose and an image pickup unit 7918 provided above the windshield in the vehicle interior mainly acquire an image in front of the vehicle 7900 . Imaging units 7912 and 7914 provided in the side mirrors mainly acquire side images of the vehicle 7900 . An imaging unit 7916 provided in the rear bumper or back door mainly acquires an image of the rear of the vehicle 7900 . An imaging unit 7918 provided above the windshield in the passenger compartment is mainly used for detecting preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, lanes, and the like.

Note that FIG. 30 shows an example of the imaging range of each of the imaging units 7910, 7912, 7914, and 7916. As shown in FIG. The imaging range a indicates the imaging range of the imaging unit 7910 provided in the front nose, the imaging ranges b and c indicate the imaging ranges of the imaging units 7912 and 7914 provided in the side mirrors, respectively, and the imaging range d is The imaging range of an imaging unit 7916 provided on the rear bumper or back door is shown. For example, by superimposing the image data captured by the imaging units 7910, 7912, 7914, and 7916, a bird's-eye view image of the vehicle 7900 viewed from above can be obtained.

The vehicle exterior information detectors 7920, 7922, 7924, 7926, 7928, and 7930 provided on the front, rear, sides, corners, and above the windshield of the vehicle interior of the vehicle 7900 may be, for example, ultrasonic sensors or radar devices. The exterior information detectors 7920, 7926, and 7930 provided above the front nose, rear bumper, back door, and windshield of the vehicle 7900 may be LIDAR devices, for example. These vehicle exterior information detection units 7920 to 7930 are mainly used to detect preceding vehicles, pedestrians, obstacles, and the like.

Returning to FIG. 29, the description continues. The vehicle exterior information detection unit 7400 causes the imaging section 7410 to capture an image of the exterior of the vehicle, and receives the captured image data. The vehicle exterior information detection unit 7400 also receives detection information from the vehicle exterior information detection unit 7420 connected thereto. When the vehicle exterior information detection unit 7420 is an ultrasonic sensor, radar device, or LIDAR device, the vehicle exterior information detection unit 7400 emits ultrasonic waves, electromagnetic waves, or the like, and receives reflected wave information. The vehicle exterior information detection unit 7400 may perform object detection processing or distance detection processing such as people, vehicles, obstacles, signs, or characters on the road surface based on the received information. The vehicle exterior information detection unit 7400 may perform environment recognition processing for recognizing rainfall, fog, road surface conditions, etc., based on the received information. The vehicle exterior information detection unit 7400 may calculate the distance to the vehicle exterior object based on the received information.

Further, the vehicle exterior information detection unit 7400 may perform image recognition processing or distance detection processing for recognizing people, vehicles, obstacles, signs, characters on the road surface, etc., based on the received image data. The vehicle exterior information detection unit 7400 performs processing such as distortion correction or alignment on the received image data, and synthesizes image data captured by different imaging units 7410 to generate a bird's-eye view image or a panoramic image. good too. The vehicle exterior information detection unit 7400 may perform viewpoint conversion processing using image data captured by different imaging units 7410 .

The vehicle interior information detection unit 7500 detects vehicle interior information. The in-vehicle information detection unit 7500 is connected to, for example, a driver state detection section 7510 that detects the state of the driver. The driver state detection unit 7510 may include a camera that captures an image of the driver, a biosensor that detects the biometric information of the driver, a microphone that collects sounds in the vehicle interior, or the like. A biosensor is provided, for example, on a seat surface, a steering wheel, or the like, and detects biometric information of a passenger sitting on a seat or a driver holding a steering wheel. The in-vehicle information detection unit 7500 may calculate the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 7510, and determine whether the driver is dozing off. You may The in-vehicle information detection unit 7500 may perform processing such as noise canceling processing on the collected audio signal.

Integrated control unit 7600 controls overall operations within vehicle control system 7000 according to various programs. An input section 7800 is connected to the integrated control unit 7600 . The input unit 7800 is realized by a device that can be input-operated by the passenger, such as a touch panel, button, microphone, switch or lever. The integrated control unit 7600 may receive data obtained by recognizing voice input from a microphone. The input unit 7800 may be, for example, a remote control device using infrared rays or other radio waves, or may be an external connection device such as a mobile phone or PDA (Personal Digital Assistant) corresponding to the operation of the vehicle control system 7000. may The input unit 7800 may be, for example, a camera, in which case the passenger can input information through gestures. Alternatively, data obtained by detecting movement of a wearable device worn by a passenger may be input. Further, the input section 7800 may include an input control circuit that generates an input signal based on information input by the passenger or the like using the input section 7800 and outputs the signal to the integrated control unit 7600, for example. A passenger or the like operates the input unit 7800 to input various data to the vehicle control system 7000 and instruct processing operations.

The storage unit 7690 may include a ROM (Read Only Memory) that stores various programs executed by the microcomputer, and a RAM (Random Access Memory) that stores various parameters, calculation results, sensor values, and the like. The storage unit 7690 may be realized by a magnetic storage device such as a HDD (Hard Disc Drive), a semiconductor storage device, an optical storage device, a magneto-optical storage device, or the like.

General-purpose communication I/F 7620 is a general-purpose communication I/F that mediates communication between various devices existing in external environment 7750 . General-purpose communication I / F 7620 is a cellular communication protocol such as GSM (registered trademark) (Global System of Mobile communications), WiMAX (registered trademark), LTE (registered trademark) (Long Term Evolution) or LTE-A (LTE-Advanced) , or other wireless communication protocols such as wireless LAN (also referred to as Wi-Fi®), Bluetooth®, and the like. General-purpose communication I / F 7620, for example, via a base station or access point, external network (e.g., Internet, cloud network or operator-specific network) equipment (e.g., application server or control server) connected to You may In addition, the general-purpose communication I / F 7620 uses, for example, P2P (Peer To Peer) technology to connect terminals (for example, terminals of drivers, pedestrians, shops, or MTC (Machine Type Communication) terminals) near the vehicle. may be connected with

Dedicated communication I/F 7630 is a communication I/F that supports a communication protocol designed for use in vehicles. Dedicated communication I / F 7630, for example, WAVE (Wireless Access in Vehicle Environment), which is a combination of lower layer IEEE 802.11p and higher layer IEEE 1609, DSRC (Dedicated Short Range Communications), or a standard protocol such as a cellular communication protocol May be implemented. The dedicated communication I/F 7630 is typically used for vehicle-to-vehicle communication, vehicle-to-infrastructure communication, vehicle-to-home communication, and vehicle-to-pedestrian communication. ) perform V2X communication, which is a concept involving one or more of the communications.

The positioning unit 7640 performs positioning by receiving, for example, GNSS signals from GNSS (Global Navigation Satellite System) satellites (for example, GPS signals from GPS (Global Positioning System) satellites), and obtains the latitude, longitude and altitude of the vehicle. Generate location information containing Note that the positioning unit 7640 may specify the current position by exchanging signals with a wireless access point, or may acquire position information from a terminal such as a mobile phone, PHS, or smart phone having a positioning function.

The beacon receiving unit 7650 receives, for example, radio waves or electromagnetic waves transmitted from a wireless station installed on the road, and acquires information such as the current position, traffic congestion, road closures, required time, and the like. Note that the function of the beacon reception unit 7650 may be included in the dedicated communication I/F 7630 described above.

In-vehicle equipment I/F 7660 is a communication interface that mediates connections between microcomputer 7610 and various in-vehicle equipment 7760 present in the vehicle. The in-vehicle device I/F 7660 may establish a wireless connection using a wireless communication protocol such as wireless LAN, Bluetooth (registered trademark), NFC (Near Field Communication), or WUSB (Wireless USB). In addition, the in-vehicle device I/F 7660 is connected via a connection terminal (and cable if necessary) not shown, USB (Universal Serial Bus), HDMI (registered trademark) (High-Definition Multimedia Interface), or MHL (Mobile A wired connection such as High-definition Link) may be established. In-vehicle equipment 7760 may include, for example, at least one of a mobile device or wearable device possessed by a passenger, or an information device carried or attached to a vehicle. In-vehicle equipment 7760 may also include a navigation device that searches for a route to an arbitrary destination. In-vehicle device I/F 7660 exchanges control signals or data signals with these in-vehicle devices 7760 .

In-vehicle network I/F 7680 is an interface that mediates communication between microcomputer 7610 and communication network 7010 . In-vehicle network I/F 7680 transmits and receives signals and the like according to a predetermined protocol supported by communication network 7010 .

The microcomputer 7610 of the integrated control unit 7600 uses at least one of 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, and an in-vehicle network I/F 7680. The vehicle control system 7000 is controlled according to various programs on the basis of the information acquired by. For example, the microcomputer 7610 calculates control target values for the driving force generator, steering mechanism, or braking device based on acquired information on the inside and outside of the vehicle, and outputs a control command to the drive system control unit 7100. good too. For example, the microcomputer 7610 realizes the functions of ADAS (Advanced Driver Assistance System) including collision avoidance or impact mitigation, follow-up driving based on inter-vehicle distance, vehicle speed maintenance driving, vehicle collision warning, or vehicle lane deviation warning. Cooperative control may be performed for the purpose of In addition, the microcomputer 7610 controls the driving force generator, the steering mechanism, the braking device, etc. based on the acquired information about the surroundings of the vehicle, thereby autonomously traveling without depending on the operation of the driver. Cooperative control may be performed for the purpose of driving or the like.

Microcomputer 7610 receives information obtained through at least one of general-purpose communication I/F 7620, dedicated communication I/F 7630, positioning unit 7640, beacon receiving unit 7650, in-vehicle device I/F 7660, and in-vehicle network I/F 7680. Based on this, three-dimensional distance information between the vehicle and surrounding objects such as structures and people may be generated, and local map information including the surrounding information of the current position of the vehicle may be created. Further, based on the acquired information, the microcomputer 7610 may predict dangers such as vehicle collisions, pedestrians approaching or entering closed roads, and generate warning signals. The warning signal may be, for example, a signal for generating a warning sound or lighting a warning lamp.

The audio/image output unit 7670 transmits at least one of audio and/or image output signals to an output device capable of visually or audibly notifying the passengers of the vehicle or the outside of the vehicle. In the example of FIG. 29, an audio speaker 7710, a display section 7720, and an instrument panel 7730 are illustrated as output devices. Display 7720 may include, for example, at least one of an on-board display and a head-up display. The display unit 7720 may have an AR (Augmented Reality) display function. Other than these devices, the output device may be headphones, a wearable device such as an eyeglass-type display worn by a passenger, or other devices such as a projector or a lamp. When the output device is a display device, the display device displays the results obtained by various processes performed by the microcomputer 7610 or information received from other control units in various formats such as text, images, tables, and graphs. Display visually. When the output device is a voice output device, the voice output device converts an audio signal including reproduced voice data or acoustic data into an analog signal and outputs the analog signal audibly.

In the example shown in FIG. 29, at least two control units connected via the communication network 7010 may be integrated as one control unit. Alternatively, an individual control unit may be composed of multiple control units. Furthermore, vehicle control system 7000 may comprise other control units not shown. Also, in the above description, some or all of the functions that any control unit has may be provided to another control unit. In other words, as long as information is transmitted and received via the communication network 7010, the predetermined arithmetic processing may be performed by any one of the control units. Similarly, sensors or devices connected to any control unit may be connected to other control units, and multiple control units may send and receive detection information to and from each other via communication network 7010. .

In the vehicle control system 7000 described above, the imaging lens and imaging device of the present disclosure can be applied to the imaging unit 7410 and the imaging units 7910, 7912, 7914, 7916, and 7918.

[5.2 Second application example]
The technology according to the present disclosure may be applied to an endoscopic surgery system.

FIG. 31 is a diagram showing an example of a schematic configuration of an endoscopic surgery system 5000 to which technology according to the present disclosure can be applied. FIG. 31 shows an operator (physician) 5067 performing surgery on a patient 5071 on a patient bed 5069 using an endoscopic surgery system 5000 . As illustrated, the endoscopic surgery system 5000 includes an endoscope 5001, other surgical tools 5017, a support arm device 5027 for supporting the endoscope 5001, and various devices for endoscopic surgery. and a cart 5037 on which is mounted.

In endoscopic surgery, instead of cutting the abdominal wall and laparotomy, tubular piercing instruments called trocars 5025a to 5025d are punctured into the abdominal wall multiple times. Then, the barrel 5003 of the endoscope 5001 and other surgical instruments 5017 are inserted into the body cavity of the patient 5071 from the trocars 5025a to 5025d. In the illustrated example, a pneumoperitoneum tube 5019 , an energy treatment instrument 5021 and forceps 5023 are inserted into the patient's 5071 body cavity as other surgical instruments 5017 . Also, the energy treatment tool 5021 is a treatment tool that performs tissue incision and ablation, blood vessel sealing, or the like, using high-frequency current or ultrasonic vibration. However, the illustrated surgical tool 5017 is merely an example, and various surgical tools generally used in endoscopic surgery, such as a forceps and a retractor, may be used as the surgical tool 5017 .

A display device 5041 displays an image of a surgical site in a body cavity of a patient 5071 photographed by the endoscope 5001 . The operator 5067 uses the energy treatment tool 5021 and the forceps 5023 to perform treatment such as excision of the affected area while viewing the image of the operated area displayed on the display device 5041 in real time. Although not shown, the pneumoperitoneum tube 5019, the energy treatment instrument 5021, and the forceps 5023 are supported by the operator 5067, an assistant, or the like during surgery.

(support arm device)
The support arm device 5027 has an arm portion 5031 extending from the base portion 5029 . In the illustrated example, the arm portion 5031 is composed of joint portions 5033a, 5033b, 5033c and links 5035a, 5035b, and is driven under the control of the arm control device 5045. The arm 5031 supports the endoscope 5001 and controls its position and orientation. As a result, stable position fixation of the endoscope 5001 can be achieved.

(Endoscope)
The endoscope 5001 is composed of a lens barrel 5003 having a predetermined length from its distal end inserted into a body cavity of a patient 5071 and a camera head 5005 connected to the proximal end of the lens barrel 5003 . In the illustrated example, an endoscope 5001 configured as a so-called rigid scope having a rigid barrel 5003 is illustrated, but the endoscope 5001 is configured as a so-called flexible scope having a flexible barrel 5003. good too.

The tip of the lens barrel 5003 is provided with an opening into which an objective lens is fitted. A light source device 5043 is connected to the endoscope 5001, and light generated by the light source device 5043 is guided to the tip of the lens barrel 5003 by a light guide extending inside the lens barrel 5003, and reaches the objective. The light is irradiated through the lens toward an observation target within the body cavity of the patient 5071 . Note that the endoscope 5001 may be a straight scope, a perspective scope, or a side scope.

An optical system and an imaging element are provided inside the camera head 5005, and reflected light (observation light) from an observation target is converged on the imaging element by the optical system. The imaging device photoelectrically converts the observation light to generate an electrical signal corresponding to the observation light, that is, an image signal corresponding to the observation image. The image signal is transmitted to a camera control unit (CCU: Camera Control Unit) 5039 as RAW data. The camera head 5005 has a function of adjusting the magnification and focal length by appropriately driving the optical system.

Note that the camera head 5005 may be provided with a plurality of imaging elements, for example, in order to support stereoscopic viewing (3D display). In this case, a plurality of relay optical systems are provided inside the lens barrel 5003 to guide the observation light to each of the plurality of imaging elements.

(various devices mounted on the cart)
The CCU 5039 is composed of a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), etc., and controls the operations of the endoscope 5001 and the display device 5041 in an integrated manner. Specifically, the CCU 5039 subjects the image signal received from the camera head 5005 to various image processing such as development processing (demosaicing) for displaying an image based on the image signal. The CCU 5039 provides the image signal subjected to the image processing to the display device 5041 . Also, the CCU 5039 transmits a control signal to the camera head 5005 to control its driving. The control signal may include information regarding imaging conditions such as magnification and focal length.

The display device 5041 displays an image based on an image signal subjected to image processing by the CCU 5039 under the control of the CCU 5039 . When the endoscope 5001 is compatible with high-resolution imaging such as 4K (horizontal pixel number 3840×vertical pixel number 2160) or 8K (horizontal pixel number 7680×vertical pixel number 4320), and/or 3D display , the display device 5041 may be one capable of high-resolution display and/or one capable of 3D display. In the case of 4K or 8K high-resolution imaging, using a display device 5041 with a size of 55 inches or more provides a more immersive feeling. Also, a plurality of display devices 5041 having different resolutions and sizes may be provided depending on the application.

The light source device 5043 is composed of a light source such as an LED (light emitting diode), for example, and supplies the endoscope 5001 with irradiation light for imaging the surgical site.

The arm control device 5045 is configured by a processor such as a CPU, for example, and operates according to a predetermined program to control driving of the arm portion 5031 of the support arm device 5027 according to a predetermined control method.

The input device 5047 is an input interface for the endoscopic surgery system 5000. FIG. The user can input various information and instructions to the endoscopic surgery system 5000 via the input device 5047 . For example, through the input device 5047, the user inputs various types of information regarding surgery, such as patient's physical information and information about the surgical technique. Further, for example, the user, via the input device 5047, instructs to drive the arm unit 5031, or instructs to change the imaging conditions (type of irradiation light, magnification, focal length, etc.) by the endoscope 5001. , an instruction to drive the energy treatment instrument 5021, or the like.

The type of the input device 5047 is not limited, and the input device 5047 may be various known input devices. As the input device 5047, for example, a mouse, keyboard, touch panel, switch, footswitch 5057 and/or lever can be applied. When a touch panel is used as the input device 5047 , the touch panel may be provided on the display surface of the display device 5041 .

Alternatively, the input device 5047 is a device worn by the user, such as a wearable device such as eyeglasses or an HMD (Head Mounted Display). is done. Also, the input device 5047 includes a camera capable of detecting the movement of the user, and performs various inputs according to the user's gestures and line of sight detected from images captured by the camera. Furthermore, the input device 5047 includes a microphone capable of picking up the user's voice, and various voice inputs are performed via the microphone. As described above, the input device 5047 is configured to be capable of inputting various kinds of information in a non-contact manner, so that a user belonging to a clean area (for example, an operator 5067) can operate a device belonging to an unclean area without contact. becomes possible. In addition, since the user can operate the device without taking his/her hands off the surgical tool, the user's convenience is improved.

The treatment instrument control device 5049 controls driving of the energy treatment instrument 5021 for tissue cauterization, incision, blood vessel sealing, or the like. The pneumoperitoneum device 5051 inflates the body cavity of the patient 5071 for the purpose of securing the visual field of the endoscope 5001 and securing the operator's working space, and injects gas into the body cavity through the pneumoperitoneum tube 5019 . send in. The recorder 5053 is a device capable of recording various types of information regarding surgery. The printer 5055 is a device capable of printing various types of information regarding surgery in various formats such as text, images, and graphs.

A particularly characteristic configuration of the endoscopic surgery system 5000 will be described in more detail below.

(support arm device)
The support arm device 5027 includes a base portion 5029 as a base and an arm portion 5031 extending from the base portion 5029 . In the illustrated example, the arm portion 5031 is composed of a plurality of joint portions 5033a, 5033b, 5033c and a plurality of links 5035a, 5035b connected by the joint portion 5033b. , the configuration of the arm portion 5031 is simplified. In practice, the shape, number and arrangement of the joints 5033a to 5033c and the links 5035a and 5035b, the directions of the rotation axes of the joints 5033a to 5033c, and the like are appropriately set so that the arm 5031 has a desired degree of freedom. obtain. For example, the arm portion 5031 may preferably be configured to have 6 or more degrees of freedom. As a result, the endoscope 5001 can be freely moved within the movable range of the arm portion 5031, so that the barrel 5003 of the endoscope 5001 can be inserted into the body cavity of the patient 5071 from a desired direction. be possible.

The joints 5033a to 5033c are provided with actuators, and the joints 5033a to 5033c are configured to be rotatable around a predetermined rotation axis by driving the actuators. By controlling the driving of the actuator by the arm control device 5045, the rotation angles of the joints 5033a to 5033c are controlled, and the driving of the arm 5031 is controlled. Thereby, control of the position and attitude of the endoscope 5001 can be realized. At this time, the arm control device 5045 can control the driving of the arm section 5031 by various known control methods such as force control or position control.

For example, when the operator 5067 appropriately performs an operation input via the input device 5047 (including the foot switch 5057), the arm control device 5045 appropriately controls the driving of the arm section 5031 in accordance with the operation input. The position and orientation of the scope 5001 may be controlled. With this control, the endoscope 5001 at the distal end of the arm section 5031 can be moved from an arbitrary position to an arbitrary position, and then fixedly supported at the position after the movement. Note that the arm portion 5031 may be operated by a so-called master-slave method. In this case, the arm portion 5031 can be remotely operated by the user via an input device 5047 installed at a location remote from the operating room.

When force control is applied, the arm control device 5045 receives an external force from the user and operates the actuators of the joints 5033a to 5033c so that the arm 5031 moves smoothly according to the external force. A so-called power assist control for driving may be performed. Accordingly, when the user moves the arm portion 5031 while directly touching the arm portion 5031, the arm portion 5031 can be moved with a relatively light force. Therefore, it becomes possible to move the endoscope 5001 more intuitively and with a simpler operation, and the user's convenience can be improved.

Here, generally, in endoscopic surgery, the endoscope 5001 is supported by a doctor called a scopist. On the other hand, the use of the support arm device 5027 makes it possible to more reliably fix the position of the endoscope 5001 without manual intervention, so that an image of the surgical site can be stably obtained. , the operation can be performed smoothly.

Note that the arm control device 5045 does not necessarily have to be provided on the cart 5037 . Also, the arm control device 5045 does not necessarily have to be one device. For example, the arm control device 5045 may be provided at each joint portion 5033a to 5033c of the arm portion 5031 of the support arm device 5027, and the arm portion 5031 is driven by the cooperation of the plurality of arm control devices 5045. Control may be implemented.

(light source device)
The light source device 5043 supplies irradiation light to the endoscope 5001 when imaging the surgical site. The light source device 5043 is composed of, for example, a white light source composed of an LED, a laser light source, or a combination thereof. At this time, when a white light source is configured by a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high precision. can be adjusted. In this case, the observation target is irradiated with laser light from each of the RGB laser light sources in a time division manner, and by controlling the drive of the imaging device of the camera head 5005 in synchronization with the irradiation timing, each of the RGB can be handled. It is also possible to pick up images by time division. According to this method, a color image can be obtained without providing a color filter in the imaging device.

Further, the driving of the light source device 5043 may be controlled so as to change the intensity of the output light every predetermined time. By controlling the drive of the imaging device of the camera head 5005 in synchronism with the timing of the change in the intensity of the light to acquire images in a time division manner and synthesizing the images, a high dynamic A range of images can be generated.

Also, the light source device 5043 may be configured to be capable of supplying light in a predetermined wavelength band corresponding to special light observation. In special light observation, for example, the wavelength dependence of light absorption in body tissues is used to irradiate a narrower band of light than the irradiation light (i.e., white light) used during normal observation, thereby observing the mucosal surface layer. So-called Narrow Band Imaging is performed in which a predetermined tissue such as a blood vessel is imaged with high contrast. Alternatively, in special light observation, fluorescence observation may be performed in which an image is obtained from fluorescence generated by irradiation with excitation light. Fluorescence observation involves irradiating body tissue with excitation light and observing fluorescence from the body tissue (autofluorescence observation), or locally injecting a reagent such as indocyanine green (ICG) into the body tissue and observing the body tissue. A fluorescent image may be obtained by irradiating excitation light corresponding to the fluorescent wavelength of the reagent. The light source device 5043 can be configured to be able to supply narrowband light and/or excitation light corresponding to such special light observation.

(camera head and CCU)
Referring to FIG. 32, the functions of camera head 5005 and CCU 5039 of endoscope 5001 will be described in more detail. FIG. 32 is a block diagram showing an example of functional configurations of the camera head 5005 and CCU 5039 shown in FIG.

Referring to FIG. 32, the camera head 5005 has a lens unit 5007, an imaging section 5009, a drive section 5011, a communication section 5013, and a camera head control section 5015 as its functions. The CCU 5039 also has a communication unit 5059, an image processing unit 5061, and a control unit 5063 as its functions. The camera head 5005 and CCU 5039 are connected by a transmission cable 5065 so as to be able to communicate bidirectionally.

First, the functional configuration of the camera head 5005 will be described. A lens unit 5007 is an optical system provided at a connection portion with the lens barrel 5003 . Observation light captured from the tip of the lens barrel 5003 is guided to the camera head 5005 and enters the lens unit 5007 . A lens unit 5007 is configured by combining a plurality of lenses including a zoom lens and a focus lens. The optical characteristics of the lens unit 5007 are adjusted so that the observation light is condensed on the light receiving surface of the imaging device of the imaging unit 5009 . Also, the zoom lens and the focus lens are configured so that their positions on the optical axis can be moved in order to adjust the magnification and focus of the captured image.

The image pickup unit 5009 is configured by an image pickup element and arranged after the lens unit 5007 . Observation light that has passed through the lens unit 5007 is condensed on the light receiving surface of the image sensor, and an image signal corresponding to the observation image is generated by photoelectric conversion. An image signal generated by the imaging unit 5009 is provided to the communication unit 5013 .

As an imaging device constituting the imaging unit 5009, for example, a CMOS (Complementary Metal Oxide Semiconductor) type image sensor, which has a Bayer arrangement and is capable of color imaging, is used. As the imaging element, for example, one capable of capturing a high-resolution image of 4K or higher may be used. By obtaining a high-resolution image of the surgical site, the operator 5067 can grasp the state of the surgical site in more detail, and the surgery can proceed more smoothly.

In addition, the imaging device constituting the imaging unit 5009 is configured to have a pair of imaging devices for acquiring image signals for right eye and left eye corresponding to 3D display. The 3D display enables the operator 5067 to more accurately grasp the depth of the living tissue in the surgical site. Note that when the imaging unit 5009 is configured as a multi-plate type, a plurality of systems of lens units 5007 are provided corresponding to each imaging element.

Also, the imaging unit 5009 does not necessarily have to be provided in the camera head 5005 . For example, the imaging unit 5009 may be provided inside the lens barrel 5003 immediately after the objective lens.

The drive unit 5011 is configured by an actuator, and moves the zoom lens and focus lens of the lens unit 5007 by a predetermined distance along the optical axis under control from the camera head control unit 5015 . Thereby, the magnification and focus of the image captured by the imaging unit 5009 can be appropriately adjusted.

Communication unit 5013 is configured by a communication device for transmitting and receiving various information to and from CCU 5039 . The communication unit 5013 transmits the image signal obtained from the imaging unit 5009 as RAW data to the CCU 5039 via the transmission cable 5065 . At this time, the image signal is preferably transmitted by optical communication in order to display the captured image of the surgical site with low latency. During surgery, the operator 5067 performs surgery while observing the state of the affected area using captured images. Therefore, for safer and more reliable surgery, moving images of the operated area are displayed in real time as much as possible. This is because it is required. When optical communication is performed, the communication unit 5013 is provided with a photoelectric conversion module that converts an electrical signal into an optical signal. After the image signal is converted into an optical signal by the photoelectric conversion module, it is transmitted to the CCU 5039 via the transmission cable 5065 .

The communication unit 5013 also receives a control signal for controlling driving of the camera head 5005 from the CCU 5039 . The control signal includes, for example, information to specify the frame rate of the captured image, information to specify the exposure value at the time of imaging, and/or information to specify the magnification and focus of the captured image. Contains information about conditions. The communication section 5013 provides the received control signal to the camera head control section 5015 . Note that the control signal from the CCU 5039 may also be transmitted by optical communication. In this case, the communication unit 5013 is provided with a photoelectric conversion module that converts an optical signal into an electrical signal, and the control signal is provided to the camera head control unit 5015 after being converted into an electrical signal by the photoelectric conversion module.

Note that the imaging conditions such as the frame rate, exposure value, magnification, and focus are automatically set by the control unit 5063 of the CCU 5039 based on the acquired image signal. That is, the endoscope 5001 is equipped with so-called AE (Auto Exposure) function, AF (Auto Focus) function, and AWB (Auto White Balance) function.

The camera head control unit 5015 controls driving of the camera head 5005 based on control signals from the CCU 5039 received via the communication unit 5013 . For example, the camera head control unit 5015 controls the driving of the imaging element of the imaging unit 5009 based on the information specifying the frame rate of the captured image and/or the information specifying the exposure during imaging. Also, for example, the camera head control unit 5015 appropriately moves the zoom lens and the focus lens of the lens unit 5007 via the driving unit 5011 based on information specifying the magnification and focus of the captured image. The camera head control unit 5015 may further have a function of storing information for identifying the lens barrel 5003 and camera head 5005 .

By arranging the lens unit 5007, the imaging unit 5009, and the like in a sealed structure with high airtightness and waterproofness, the camera head 5005 can be made resistant to autoclave sterilization.

Next, the functional configuration of the CCU 5039 will be described. A communication unit 5059 is configured by a communication device for transmitting and receiving various information to and from the camera head 5005 . The communication unit 5059 receives image signals transmitted from the camera head 5005 via the transmission cable 5065 . At this time, as described above, the image signal can be preferably transmitted by optical communication. In this case, the communication unit 5059 is provided with a photoelectric conversion module that converts an optical signal into an electrical signal for optical communication. The communication unit 5059 provides the image processing unit 5061 with the image signal converted into the electrical signal.

The communication unit 5059 also transmits a control signal for controlling driving of the camera head 5005 to the camera head 5005 . The control signal may also be transmitted by optical communication.

An image processing unit 5061 performs various types of image processing on the image signal, which is RAW data transmitted from the camera head 5005 . The image processing includes, for example, development processing, image quality improvement processing (band enhancement processing, super-resolution processing, NR (noise reduction) processing and/or camera shake correction processing, etc.), and/or enlargement processing (electronic zoom processing). etc., various known signal processing is included. Also, the image processing unit 5061 performs detection processing on the image signal for performing AE, AF, and AWB.

The image processing unit 5061 is configured by a processor such as a CPU or GPU, and the processor operates according to a predetermined program to perform the image processing and detection processing described above. Note that when the image processing unit 5061 is composed of a plurality of GPUs, the image processing unit 5061 appropriately divides information related to image signals and performs image processing in parallel by the plurality of GPUs.

The control unit 5063 performs various controls related to the imaging of the surgical site by the endoscope 5001 and the display of the captured image. For example, the control unit 5063 generates control signals for controlling driving of the camera head 5005 . At this time, if the imaging condition is input by the user, the control unit 5063 generates a control signal based on the input by the user. Alternatively, when the endoscope 5001 is equipped with the AE function, the AF function, and the AWB function, the control unit 5063 optimizes the exposure value, focal length, and A white balance is calculated appropriately and a control signal is generated.

Further, the control unit 5063 causes the display device 5041 to display an image of the surgical site based on the image signal subjected to image processing by the image processing unit 5061 . At this time, the control unit 5063 recognizes various objects in the surgical site image using various image recognition techniques. For example, the control unit 5063 detects the shape, color, and the like of the edges of objects included in the surgical site image, thereby detecting surgical tools such as forceps, specific body parts, bleeding, mist when using the energy treatment tool 5021, and the like. can recognize. When displaying the image of the surgical site on the display device 5041, the control unit 5063 uses the recognition result to superimpose and display various surgical assistance information on the image of the surgical site. By superimposing and displaying the surgery support information and presenting it to the operator 5067, it becomes possible to proceed with the surgery more safely and reliably.

A transmission cable 5065 connecting the camera head 5005 and the CCU 5039 is an electrical signal cable compatible with electrical signal communication, an optical fiber compatible with optical communication, or a composite cable of these.

Here, in the illustrated example, wired communication is performed using the transmission cable 5065, but communication between the camera head 5005 and the CCU 5039 may be performed wirelessly. If the communication between them is performed wirelessly, it is not necessary to lay the transmission cable 5065 in the operating room, so the situation that the transmission cable 5065 interferes with the movement of the medical staff in the operating room can be resolved.

An example of the endoscopic surgery system 5000 to which the technology according to the present disclosure can be applied has been described above. Although the endoscopic surgery system 5000 has been described as an example here, the system to which the technique according to the present disclosure can be applied is not limited to such an example. For example, the technology according to the present disclosure may be applied to a flexible endoscope system for inspection and a microsurgery system.

The technology according to the present disclosure can be suitably applied to the camera head 5005 among the configurations described above. In particular, the imaging lens of the present disclosure can be suitably applied to the lens unit 5007 of the camera head 5005.

<6. Other Embodiments>
The technology according to the present disclosure is not limited to the description of the above embodiments and examples, and various modifications are possible.

For example, the shapes and numerical values of the respective parts shown in the above embodiment and example are merely examples of implementation for implementing the present technology, and the technical scope of the present technology is limited by these. It should not be interpreted.

For example, the configuration may include a number of lenses different from the number of lenses shown in the above embodiment and example. Furthermore, the configuration may be further provided with a lens having substantially no refractive power.

Further, for example, the present technology can have the following configurations.
According to the present technology having the following configuration, in the configuration consisting of the first to third lens groups, it is possible to achieve high optical performance while maintaining a small size and a large aperture, and to suppress fluctuations in the angle of view during focusing. The power of the lens group and the lateral magnification are optimized. As a result, it is possible to provide an imaging lens and an imaging apparatus that are small in size and have a large aperture, yet have high optical performance, and in which fluctuations in the angle of view during focusing are suppressed.

[1]
From the object side to the image plane side,
a first lens group having at least two negative lenses;
a second lens group having positive refractive power;
and a third lens group having negative refractive power,
When the subject distance changes from infinity to short, the first lens group is fixed, and the second lens group or the second lens group and the third lens group move in the optical axis direction. Focusing
An imaging lens that satisfies the following conditional expression.
-1.05<f2/f3<-0.25 (1)
1.38<β3 (2)
0.2<(R11-R12)/(R11+R12)<0.8 (3)
however,
f2: focal length of the second lens group f3: focal length of the third lens group β3: lateral magnification of the third lens group R1: radius of curvature of the object-side surface of the most object-side lens R2: most object-side is the radius of curvature of the image-side surface of the lens.
[2]
The imaging lens according to [1] above, which satisfies the following conditional expression.
1.0<f2/f<2.1 (4)
however,
f: The focal length of the entire system when focused to infinity.
[3]
The imaging lens according to the above [1] or [2], which satisfies the following conditional expression.
0.5<f2_Llast/f2<4.5 (5)
however,
f2_Llast: The focal length of the lens closest to the image plane in the second lens group.
[4]
The imaging lens according to any one of [1] to [3] above, which satisfies the following conditional expression.
1.0<|K2|<3.5 (6)
however,
K2: focus sensitivity of the second lens group when focused to infinity K2=|(β3 ² )×(1−β2 ² )|
β2: Lateral magnification of the second lens group β3: Lateral magnification of the third lens group.
[5]
The imaging lens according to any one of [1] to [4] above, which satisfies the following conditional expression.
0.3<BF/f<2.5 (7)
however,
f: focal length of the entire system when focused to infinity BF: distance from the lens surface closest to the image plane to the image plane.
[6]
The imaging lens according to any one of [1] to [5] above, which has an aperture stop closer to the object side than the second lens group.
[7]
The imaging lens according to any one of [1] to [6] above, which satisfies the following conditional expression.
1.5<nL1<2.2 (8)
however,
nL1: The refractive index of the lens closest to the object side.
[8]
The imaging lens according to any one of [1] to [7] above, wherein the first lens group, the second lens group, and the third lens group as a whole have at least ten lenses.
[9]
From the object side to the image plane side,
a first lens group consisting of a lens group 1a, an aperture stop, and a lens group 1b, and having at least two negative lenses;
a second lens group comprising at least one positive lens and at least one negative lens and having positive refractive power;
and a third lens group having negative refractive power,
When the subject distance changes from infinity to short, the first lens group is fixed, and the second lens group or the second lens group and the third lens group move in the optical axis direction. Focusing
An imaging lens that satisfies the following conditional expression.
-1.05<f2/f3<-0.25 (1)
|β2|<0.45 (9)
however,
f2: focal length of the second lens group f3: focal length of the third lens group β2: lateral magnification of the second lens group.
[10]
The imaging lens according to [9] above, which satisfies the following conditional expression.
1.0<f2/f<2.1 (4)
however,
f: The focal length of the entire system when focused to infinity.
[11]
The imaging lens according to [9] or [10] above, which satisfies the following conditional expression.
0.5<f2_Llast/f2<4.5 (5)
however,
f2_Llast: The focal length of the lens closest to the image plane in the second lens group.
[12]
The imaging lens according to any one of [9] to [11] above, which satisfies the following conditional expression.
1.0<|K2|<3.5 (6)
however,
K2: focus sensitivity of the second lens group when focused to infinity K2=|(β3 ² )×(1−β2 ² )|
β2: Lateral magnification of the second lens group β3: Lateral magnification of the third lens group.
[13]
The imaging lens according to any one of [9] to [12] above, which satisfies the following conditional expression.
0.3<BF/f<2.5 (7)
however,
f: focal length of the entire system when focused to infinity BF: distance from the lens surface closest to the image plane to the image plane.
[14]
The imaging lens according to any one of [9] to [13] above, which satisfies the following conditional expression.
1.5<nL1<2.2 (8)
however,
nL1: The refractive index of the lens closest to the object side.
[15]
The imaging lens according to any one of [9] to [14] above, wherein the first lens group, the second lens group, and the third lens group as a whole have at least 11 lenses.
[16]
An imaging lens, and an imaging element that outputs an imaging signal corresponding to an optical image formed by the imaging lens,
The imaging lens is
From the object side to the image plane side,
a first lens group having at least two negative lenses;
a second lens group having positive refractive power;
and a third lens group having negative refractive power,
When the subject distance changes from infinity to short, the first lens group is fixed, and the second lens group or the second lens group and the third lens group move in the optical axis direction. Focusing
An imaging device that satisfies the following conditional expression.
-1.05<f2/f3<-0.25 (1)
1.38<β3 (2)
0.2<(R11-R12)/(R11+R12)<0.8 (3)
however,
f2: focal length of the second lens group f3: focal length of the third lens group β3: lateral magnification of the third lens group R1: radius of curvature of the object-side surface of the most object-side lens R2: most object-side is the radius of curvature of the image-side surface of the lens.
[17]
An imaging lens, and an imaging element that outputs an imaging signal corresponding to an optical image formed by the imaging lens,
The imaging lens is
From the object side to the image plane side,
a first lens group consisting of a lens group 1a, an aperture stop, and a lens group 1b, and having at least two negative lenses;
a second lens group comprising at least one positive lens and at least one negative lens and having positive refractive power;
and a third lens group having negative refractive power,
When the subject distance changes from infinity to short, the first lens group is fixed, and the second lens group or the second lens group and the third lens group move in the optical axis direction. Focusing
An imaging device that satisfies the following conditional expression.
-1.05<f2/f3<-0.25 (1)
|β2|<0.45 (9)
however,
f2: focal length of the second lens group f3: focal length of the third lens group β2: lateral magnification of the second lens group.
[18]
The imaging lens according to any one of the above [1] to [15], further comprising a lens having substantially no refractive power.
[19]
The imaging device according to [16] or [17] above, wherein the imaging lens further includes a lens having substantially no refractive power.

G1... 1st lens group, G1a... 1a lens group, G1b... 1b lens group, G2... 2nd lens group, G3... 3rd lens group, FL... optical member, L1 to L12... lens, St... aperture Aperture Z1 Optical axis 1 to 9 Imaging lens 10 Camera block 11 Imaging lens 12 Imaging element 20 Camera signal processing unit 30 Image processing unit 40 LCD 50 R/ W (reader/writer) 60 CPU 70 input section 80 lens driving control section 100 imaging device 1000 memory card 5005 camera head 5007 lens unit 5009 imaging section 7410 imaging units, 7910, 7912, 7914, 7916, 7918... imaging units.

Claims (17)

From the object side to the image plane side,
a first lens group having at least two negative lenses;
a second lens group having positive refractive power;
and a third lens group having negative refractive power,
When the subject distance changes from infinity to short, the first lens group is fixed, and the second lens group or the second lens group and the third lens group move in the optical axis direction. Focusing
An imaging lens that satisfies the following conditional expression.
-1.05<f2/f3<-0.25 (1)
1.38<β3 (2)
0.2<(R11-R12)/(R11+R12)<0.8 (3)
however,
f2: focal length of the second lens group f3: focal length of the third lens group β3: lateral magnification of the third lens group R1: radius of curvature of the object-side surface of the most object-side lens R2: most object-side is the radius of curvature of the image-side surface of the lens. The imaging lens according to claim 1, which satisfies the following conditional expression.
1.0<f2/f<2.1 (4)
however,
f: The focal length of the entire system when focused to infinity. The imaging lens according to claim 1, which satisfies the following conditional expression.
0.5<f2_Llast/f2<4.5 (5)
however,
f2_Llast: The focal length of the lens closest to the image plane in the second lens group. The imaging lens according to claim 1, which satisfies the following conditional expression.
1.0<|K2|<3.5 (6)
however,
K2: focus sensitivity of the second lens group when focused to infinity K2=|(β3 ² )×(1−β2 ² )|
β2: Lateral magnification of the second lens group β3: Lateral magnification of the third lens group. The imaging lens according to claim 1, which satisfies the following conditional expression.
0.3<BF/f<2.5 (7)
however,
f: focal length of the entire system when focused to infinity BF: distance from the lens surface closest to the image plane to the image plane. The imaging lens according to claim 1, further comprising an aperture stop on the object side of the second lens group. The imaging lens according to claim 1, which satisfies the following conditional expression.
1.5<nL1<2.2 (8)
however,
nL1: The refractive index of the lens closest to the object side. The imaging lens according to Claim 1, wherein the first lens group, the second lens group, and the third lens group as a whole have at least ten lenses. From the object side to the image plane side,
a first lens group consisting of a lens group 1a, an aperture stop, and a lens group 1b, and having at least two negative lenses;
a second lens group comprising at least one positive lens and at least one negative lens and having positive refractive power;
and a third lens group having negative refractive power,
When the subject distance changes from infinity to short, the first lens group is fixed, and the second lens group or the second lens group and the third lens group move in the optical axis direction. Focusing
An imaging lens that satisfies the following conditional expression.
-1.05<f2/f3<-0.25 (1)
|β2|<0.45 (9)
however,
f2: focal length of the second lens group f3: focal length of the third lens group β2: lateral magnification of the second lens group. The imaging lens according to claim 9, which satisfies the following conditional expression.
1.0<f2/f<2.1 (4)
however,
f: The focal length of the entire system when focused to infinity. The imaging lens according to claim 9, which satisfies the following conditional expression.
0.5<f2_Llast/f2<4.5 (5)
however,
f2_Llast: The focal length of the lens closest to the image plane in the second lens group. The imaging lens according to claim 9, which satisfies the following conditional expression.
1.0<|K2|<3.5 (6)
however,
K2: focus sensitivity of the second lens group when focused to infinity K2=|(β3 ² )×(1−β2 ² )|
β2: Lateral magnification of the second lens group β3: Lateral magnification of the third lens group. The imaging lens according to claim 9, which satisfies the following conditional expression.
0.3<BF/f<2.5 (7)
however,
f: focal length of the entire system when focused to infinity BF: distance from the lens surface closest to the image plane to the image plane. The imaging lens according to claim 9, which satisfies the following conditional expression.
1.5<nL1<2.2 (8)
however,
nL1: The refractive index of the lens closest to the object side. The imaging lens according to Claim 9, wherein the first lens group, the second lens group, and the third lens group as a whole have at least eleven lenses. An imaging lens, and an imaging element that outputs an imaging signal corresponding to an optical image formed by the imaging lens,
The imaging lens is
From the object side to the image plane side,
a first lens group having at least two negative lenses;
a second lens group having positive refractive power;
and a third lens group having negative refractive power,
When the subject distance changes from infinity to short, the first lens group is fixed, and the second lens group or the second lens group and the third lens group move in the optical axis direction. Focusing
An imaging device that satisfies the following conditional expression.
-1.05<f2/f3<-0.25 (1)
1.38<β3 (2)
0.2<(R11-R12)/(R11+R12)<0.8 (3)
however,
f2: focal length of the second lens group f3: focal length of the third lens group β3: lateral magnification of the third lens group R1: radius of curvature of the object-side surface of the most object-side lens R2: most object-side is the radius of curvature of the image-side surface of the lens. An imaging lens, and an imaging element that outputs an imaging signal corresponding to an optical image formed by the imaging lens,
The imaging lens is
From the object side to the image plane side,
a first lens group consisting of a lens group 1a, an aperture stop, and a lens group 1b, and having at least two negative lenses;
a second lens group comprising at least one positive lens and at least one negative lens and having positive refractive power;
and a third lens group having negative refractive power,
When the subject distance changes from infinity to short, the first lens group is fixed, and the second lens group or the second lens group and the third lens group move in the optical axis direction. Focusing
An imaging device that satisfies the following conditional expression.
-1.05<f2/f3<-0.25 (1)
|β2|<0.45 (9)
however,
f2: focal length of the second lens group f3: focal length of the third lens group β2: lateral magnification of the second lens group.

Images