JP7616212B2 - Zoom lens and imaging device - Google Patents

Description

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

Imaging devices using solid-state imaging elements require imaging optical systems with a wide angle of view and high performance (high resolution) across the entire screen, and various optical systems have been proposed (see, for example, Patent Documents 1 to 3).

JP 2011-227124 A JP 2007-94174 A JP 2019-40219 A

In recent years, there has been a strong demand for imaging optical systems used in imaging devices to not only have a wide angle of view and high resolution, but also to reduce fluctuations in the angle of view during focusing, which is important in fields such as video.

It is desirable to provide a zoom lens that enables smooth focusing operation while minimizing fluctuations in the angle of view and aberration during focusing, and an imaging device equipped with such a zoom lens.

A zoom lens according to an embodiment of the present disclosure includes, in order from the object side to the image surface side, a negative meniscus lens with a convex surface facing the object side disposed closest to the object surface, a first lens group having negative refractive power, a second lens group having negative refractive power and moving toward the image surface side during focusing, an aperture stop as a main aperture, a third lens group having positive refractive power, and a fourth lens group having positive refractive power, wherein the first lens group has a positive lens disposed closer to the image surface side than the negative meniscus lens, and when zooming from the wide-angle end to the telephoto end, the first lens group and the second lens group move toward the image surface side and the third lens group and the fourth lens group move toward the object side so that a distance between adjacent lens groups changes, and the following conditional expression is satisfied:
0.2<f1/f2<0.9...(1)
however,
f1: focal length of the first lens group, and f2: focal length of the second lens group.

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

A zoom lens or imaging device according to one embodiment of the present disclosure is composed of three or more groups as a whole, and the configuration of each lens group is optimized to enable smooth focusing operations while minimizing fluctuations in the angle of view and aberrations during focusing.

1 is a lens cross-sectional view showing a first configuration example (Example 1) of a zoom lens according to an embodiment of the present disclosure. FIG. 4 is a lens cross-sectional view showing a second configuration example (Example 2) of a zoom lens according to an embodiment. FIG. 11 is a lens cross-sectional view showing a third configuration example (Example 3) of a zoom lens according to an embodiment. 4A to 4C are aberration diagrams illustrating longitudinal aberration of the zoom lens according to Example 1 at the wide-angle end and when focused on infinity. 5A and 5B are aberration diagrams illustrating longitudinal aberration of the zoom lens according to Example 1 at the wide-angle end when focusing on a close object. 5A and 5B are aberration diagrams illustrating longitudinal aberration of the zoom lens according to Example 1 when the zoom lens is at an intermediate focal length and focused at infinity. 5A and 5B are aberration diagrams illustrating longitudinal aberration of the zoom lens according to Example 1 at an intermediate focal length and when focusing on a close object. 5A to 5C are aberration diagrams illustrating longitudinal aberration of the zoom lens according to Example 1 at the telephoto end and when focused on infinity. 5A and 5B are aberration diagrams illustrating longitudinal aberration of the zoom lens according to Example 1 at the telephoto end when focusing on a close object. 5A and 5B are aberration diagrams illustrating lateral aberration of the zoom lens according to Example 1 at the wide-angle end and when focused on infinity. 5A to 5C are aberration diagrams illustrating lateral aberration of the zoom lens according to Example 1 at the wide-angle end when focusing on a close object. 5A to 5C are aberration diagrams illustrating lateral aberration of the zoom lens according to Example 1 when the zoom lens is at an intermediate focal length and focused at infinity. 5A to 5C are aberration diagrams illustrating lateral aberration of the zoom lens according to Example 1 at an intermediate focal length and when focusing on a close object. 5A to 5C are aberration diagrams illustrating lateral aberration of the zoom lens according to Example 1 at the telephoto end and focused on infinity. 5A to 5C are aberration diagrams illustrating lateral aberration of the zoom lens according to Example 1 at the telephoto end when focusing on a close object. 8A and 8B are aberration diagrams illustrating longitudinal aberration of the zoom lens according to Example 2 at the wide-angle end and when focused on infinity. 8A and 8B are aberration diagrams illustrating longitudinal aberration of the zoom lens according to Example 2 at the wide-angle end when focusing on a close object. 8A and 8B are aberration diagrams illustrating longitudinal aberration of the zoom lens according to Example 2 when the zoom lens is at an intermediate focal length and focused on infinity. 8A and 8B are aberration diagrams illustrating longitudinal aberration of the zoom lens according to Example 2 at an intermediate focal length and when focusing on a close object. 8A and 8B are aberration diagrams illustrating longitudinal aberration of the zoom lens according to Example 2 at the telephoto end and when focused on infinity. 8A and 8B are aberration diagrams illustrating longitudinal aberration of the zoom lens according to Example 2 at the telephoto end when focusing on a close object. 8A to 8C are aberration diagrams illustrating lateral aberration of the zoom lens according to Example 2 at the wide-angle end and when focused on infinity. 8A and 8B are aberration diagrams illustrating lateral aberration of the zoom lens according to Example 2 at the wide-angle end when focusing on a close object. 8A to 8C are aberration diagrams illustrating lateral aberration of the zoom lens according to Example 2 when the zoom lens is at an intermediate focal length and focused on infinity. 8A to 8C are aberration diagrams illustrating lateral aberration of the zoom lens according to Example 2 at an intermediate focal length and when focusing on a close object. 8A and 8B are aberration diagrams illustrating lateral aberration of the zoom lens according to Example 2 at the telephoto end and when focused on infinity. 8A and 8B are aberration diagrams illustrating lateral aberration of the zoom lens according to Example 2 at the telephoto end when focusing on a close object. 11A and 11B are aberration diagrams illustrating longitudinal aberration of the zoom lens according to Example 3 at the wide-angle end and when focused on infinity. 11A and 11B are aberration diagrams illustrating longitudinal aberration of the zoom lens according to Example 3 at the wide-angle end when focusing on a close object. 11A and 11B are aberration diagrams illustrating longitudinal aberration of the zoom lens according to Example 3 when the zoom lens is at an intermediate focal length and focused on infinity. 11A and 11B are aberration diagrams illustrating longitudinal aberration of the zoom lens according to Example 3 at an intermediate focal length and when focusing on a close object. 11A and 11B are aberration diagrams illustrating longitudinal aberration of the zoom lens according to Example 3 at the telephoto end and focused on infinity. 11A and 11B are aberration diagrams illustrating longitudinal aberration of the zoom lens according to Example 3 at the telephoto end when focusing on a close object. 11A and 11B are aberration diagrams illustrating lateral aberration at the wide-angle end of the zoom lens according to Example 3 when focused on infinity. 11A and 11B are aberration diagrams illustrating lateral aberration of the zoom lens according to Example 3 at the wide-angle end when focusing on a close object. 11A and 11B are aberration diagrams illustrating lateral aberration of the zoom lens according to Example 3 when the zoom lens is at an intermediate focal length and focused on infinity. 11A and 11B are aberration diagrams illustrating lateral aberration of the zoom lens according to Example 3 at an intermediate focal length and when focusing on a close object. 11A and 11B are aberration diagrams illustrating lateral aberration at the telephoto end of the zoom lens according to Example 3 when focused on infinity. 11A and 11B are aberration diagrams illustrating lateral aberration of the zoom lens according to Example 3 at the telephoto end when focusing on a close object. FIG. 1 is a block diagram showing an example of the configuration of an imaging device. 1 is a block diagram showing an example of a schematic configuration of a vehicle control system; 4 is an explanatory diagram showing an example of the installation positions of an outside-vehicle information detection unit and an imaging unit; FIG. 1 is a configuration diagram showing an example of a schematic configuration of an endoscopic surgery system. A block diagram showing an example of the functional configuration of the camera head and CCU shown in Figure 43.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be made in the following order.
0. Comparative Example 1. Basic Lens Configuration 2. Actions and Effects 3. Example of Application to Imaging Device 4. Example of Lens Numerical Values 5. Application Examples 6. Other Embodiments

<0. Comparative Example>
As a wide-angle imaging optical system, a retrofocus imaging optical system is disclosed in Patent Document 1. Patent Document 1 discloses a retrofocus wide-angle lens with a single focal length and a photographing angle of view of 120 degrees, which includes, in order from the object side, a first lens group with negative refractive power, an aperture stop, and a second lens group with positive refractive power.

Patent Document 2 also discloses a negative-lead type zoom lens as a wide-angle imaging optical system, in which a lens group with negative refractive power is in the foreground (located closest to the object side). Patent Document 2 discloses a wide-angle zoom lens consisting of, from the object side, a first lens group with negative refractive power and a second lens group with positive refractive power, with a total shooting angle of 114.7 degrees at the wide-angle end and a zoom ratio of about 1.65. Patent Document 2 also discloses a wide-angle zoom lens consisting of, from the object side, a first lens group with negative refractive power, a second lens group with positive refractive power, and a third lens group with positive refractive power, with a total shooting angle of 114.7 degrees at the wide-angle end and a zoom ratio of about 1.65.

On the other hand, in recent years, there has been a strong demand for imaging optical systems used in imaging devices that not only have a wide angle of view and high resolution, but also reduce fluctuations in the angle of view during focusing, which is important in fields such as video. In order to reduce fluctuations in the angle of view during focusing, it is preferable to select a lens group that has little fluctuation in focal length and distortion aberration during focusing as the focus group. In contrast, in the case of the ultra-wide-angle zoom lens disclosed in Patent Document 3, a group with little degree of freedom and large fluctuations in focal length is used as the focus group, resulting in a zoom configuration with large fluctuations in the angle of view.

Therefore, there is a need for the development of a zoom lens that allows for smooth focusing operation, has minimal fluctuations in the angle of view and aberration during focusing, and provides good aberration correction, as well as an imaging device equipped with such a zoom lens.

<1. Basic lens structure>
Fig. 1 shows a first configuration example of a zoom lens according to an embodiment of the present disclosure, which corresponds to the configuration of Example 1 described later. Fig. 2 shows a second configuration example of a zoom lens according to an embodiment, which corresponds to the configuration of Example 2 described later. Fig. 3 shows a third configuration example of a zoom lens according to an embodiment, which corresponds to the configuration of Example 3 described later.

In Figure 1 etc., Z1 indicates the optical axis. An optical member LF such as a cover glass for protecting the image sensor may be arranged between the zoom lenses 1 to 3 according to the first to third configuration examples and the image plane. 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 LF.

Below, the configuration of a zoom lens according to one embodiment of the present disclosure will be described in association with zoom lenses 1 to 3 according to each of the configuration examples shown in Figure 1 etc., as appropriate, but the technology according to the present disclosure is not limited to the configuration examples shown in the figures.

A zoom lens according to one embodiment comprises, along an optical axis Z1, in order from the object side to the image plane side, a first lens group GR1, an aperture stop St, a second lens group GR2, and a subsequent group including at least one lens group.

The first lens group GR1 has a negative refractive power overall. A negative meniscus lens with a convex surface facing the object side is disposed closest to the object side in the first lens group GR1. It is desirable that the first lens group GR1 has at least one positive lens disposed closer to the image surface than the negative meniscus lens.

The second lens group GR2 has a negative refractive power overall. As a focus group, the second lens group GR2 moves toward the image surface during focusing. It is desirable that the second lens group GR2 be composed of a single lens component. Here, the single lens component may be a single lens or a cemented lens in which multiple lenses are cemented together.

The rear group includes at least one lens group having positive refractive power. Figures 1 to 3 show an example of a configuration in which the rear group is composed of a third lens group GR3 having positive refractive power and a fourth lens group GR4 having positive refractive power.

In a zoom lens according to one embodiment, when zooming from the wide-angle end to the telephoto end, the spacing between adjacent lens groups changes along the optical axis Z1. Note that Figures 1 to 3 show the lens arrangement at the wide-angle end and when focusing at infinity. Arrows in Figures 1 to 3 show an outline of the movement trajectory of each lens group when zooming from the wide-angle end to the telephoto end. Also, Figures 1 to 3 show the direction of movement of the focus group when focusing from infinity to a close distance.

In addition, it is desirable for the zoom lens of one embodiment to further satisfy certain conditional expressions, etc., which will be described later.

<2. Actions and Effects>
Next, the operation and effects of the zoom lens according to the embodiment of the present disclosure will be described, along with a more desirable configuration of the zoom lens according to the embodiment of the present disclosure.
It should be noted that the effects described in this specification are merely examples and are not limiting, and other effects may also be obtained.

According to one embodiment of the zoom lens, the overall configuration is made up of three or more lens groups, and the configuration of each lens group is optimized, making it possible to realize a zoom lens and imaging device that allows for quick focusing operations while minimizing fluctuations in the angle of view and aberrations during focusing.

In one embodiment of the zoom lens, a first lens group GR1 with negative refractive power, a second lens group GR2 with negative refractive power, and a subsequent group including one lens group with positive refractive power are arranged from the object side in a retrofocus type power arrangement, making it possible to construct a compact ultra-wide-angle lens.

Furthermore, in a zoom lens according to one embodiment, an aperture stop St is disposed between the second lens group GR2 and the lens group (third lens group GR3) that is positioned closest to the object among the succeeding groups, thereby making it possible to cut out the amount of unnecessary light at intermediate image heights in a balanced manner, thereby making it possible to obtain higher optical performance.

In addition, according to the zoom lens of one embodiment, the second lens group GR2 has a minimal lens configuration consisting of a single lens component, making it possible to achieve a smooth focusing operation.

Here, it is desirable for the zoom lens according to one embodiment to satisfy the following conditional expression (1).
0.2<f1/f2<0.9...(1)
however,
f1: focal length of the first lens group GR1, and f2: focal length of the second lens group GR2.

Conditional formula (1) is a conditional formula for setting the relationship between the focal length of the first lens group GR1 and the focal length of the second lens group GR2. By satisfying conditional formula (1), it is possible to reduce the fluctuation in the angle of view and the fluctuation in aberration during focusing. If the lower limit of conditional formula (1) is not satisfied, the focal length of the second lens group GR2 becomes large, and the amount of movement required during focusing increases, resulting in an increase in the size of the optical system. On the other hand, if the upper limit of conditional formula (1) is exceeded, the focal length of the second lens group GR2 becomes small, and the fluctuation in aberration during focusing increases, making it difficult to achieve high image quality.

In order to more effectively realize the effect of the above-mentioned conditional expression (1), it is more desirable to set the numerical range of the conditional expression (1) as shown in the following conditional expression (1A).
0.45<f1/f2<0.86...(1A)

Moreover, it is desirable for the zoom lens according to one embodiment to satisfy the following conditional expression (2).
0.7<Bfw/fw<1.4...(2)
however,
Bfw: back focus at the wide-angle end fw: focal length of the entire system at the wide-angle end.

Conditional formula (2) is stipulated so that the size of the optical system is small and lightweight, and is a conditional formula for appropriately setting the relationship between the focal length of the entire system at the wide-angle end and the back focus at the wide-angle end. If the lower limit of conditional formula (2) is not met, the focal length at the wide-angle end becomes long, making it difficult to achieve a wide angle. On the other hand, if the upper limit of conditional formula (2) is exceeded, the back focus becomes too long, and the asymmetry of the power arrangement required for widening the angle increases, making it difficult to correct various aberrations and achieving high image quality.

In order to more effectively realize the effect of the above-mentioned conditional expression (2), it is more desirable to set the numerical range of the conditional expression (2) as shown in the following conditional expression (2A).
1.0<Bfw/fw<1.3...(2A)

In addition, in a zoom lens according to one embodiment, it is desirable that the aperture diaphragm St moves independently of the second lens group GR2 and the lens group (third lens group GR3) that is located closest to the object among the succeeding groups, and that the aperture diameter changes, when zooming from the wide-angle end to the telephoto end. By moving the aperture diaphragm St independently of the second lens group GR2 and the third lens group GR3, and changing the aperture diameter, when zooming from the wide-angle end to the telephoto end, it is possible to cut out unnecessary light that is likely to enter at intermediate image heights, and it is possible to improve the optical performance over the entire zoom range, especially at the wide-angle end.

In addition, in the zoom lens according to one embodiment, it is preferable to further provide a sub-diaphragm, which is arranged closer to the image surface than the aperture diaphragm St and whose aperture diameter changes when zooming from the wide-angle end to the telephoto end, as a flare cutter. For example, as in the configuration example shown in FIG. 1 to FIG. 3, it is preferable to arrange the first sub-diaphragm (first flare cutter FC1) or the second sub-diaphragm (second flare cutter FC2) on the most image surface side of the third lens group GR3. It is also preferable to arrange the second sub-diaphragm (second flare cutter FC2) in the lens group (fourth lens group GR4) arranged closest to the image surface side in the succeeding group. By arranging the sub-diaphragm whose aperture diameter changes during zooming closer to the image surface than the aperture diaphragm St, it is possible to cut unnecessary light that is likely to enter at intermediate image heights and cannot be cut by the aperture diaphragm St alone, and it is possible to improve the optical performance in the entire zoom range, especially the optical performance on the wide-angle end side.

Moreover, it is desirable for the zoom lens according to one embodiment to satisfy the following conditional expression (3).
0.9<|R2f-R2r|/|R2f+R2r|<10.0...(3)
however,
R2f: radius of curvature of the surface of the second lens group GR2 closest to the object side, and R2r: radius of curvature of the surface of the second lens group GR2 closest to the image surface.

Conditional formula (3) is stipulated to suppress the occurrence of various aberrations during focusing and to suppress fluctuations in the angle of view, and is a conditional formula for appropriately setting the relationship between the radius of curvature of the surface of the second lens group GR2 closest to the object side and the radius of curvature of the surface of the second lens group GR2 closest to the image plane side. If the lower limit of conditional formula (3) is not met, the focal length at the wide-angle end becomes long, making it difficult to achieve a wide angle. On the other hand, if the upper limit of conditional formula (3) is exceeded, the back focus becomes too long, and the asymmetry of the power arrangement required for widening the angle increases, making it difficult to correct various aberrations and achieve high image quality.

In order to more effectively realize the effect of the above-mentioned conditional expression (3), it is more desirable to set the numerical range of the conditional expression (3) as shown in the following conditional expression (3A).
1.2<|R2f-R2r|/|R2f+R2r|<7.8...(3A)

3. Application example to imaging device
Next, a specific example of application of the zoom lens according to an embodiment of the present disclosure to an imaging device will be described.

Figure 40 shows an example of the configuration of an imaging device 100 to which a zoom lens according to one embodiment is applied. The imaging device 100 is, for example, a digital still camera, and includes a camera block 10, a camera signal processing unit 20, an image processing unit 30, an LCD (Liquid Crystal Display) 40, an R/W (Reader/Writer) 50, a CPU (Central Processing Unit) 60, an input unit 70, and a lens drive control unit 80.

The camera block 10 is responsible for the imaging function and has a zoom lens including an imaging lens 11, and an imaging element 12 such as a CCD (Charge Coupled Devices) or a CMOS (Complementary Metal Oxide Semiconductor). The imaging element 12 converts the optical image formed by the imaging lens 11 into an electrical signal, and outputs an imaging signal (image signal) corresponding to the optical image. The zoom lenses 1 to 3 according to the configuration examples shown in Figures 1 to 3 can be used as the imaging lens 11.

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

The image processing unit 30 performs recording and playback processing of image signals, and is configured to perform compression encoding, decompression decoding processing of image signals based on a specified image data format, as well as conversion processing of data specifications such as resolution.

The LCD 40 has a function of displaying various data such as the operating status of the user on the 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 is removable from a slot connected to the R/W 50.

The CPU 60 functions as a control processing unit that controls each circuit block provided in the imaging device 100, and controls each circuit block based on an instruction input signal from the input unit 70. The input unit 70 is composed of various switches and the like that are operated as required by the user. The input unit 70 is composed of, for example, a shutter release button for performing a shutter operation and a selection switch for selecting an operation mode, and is configured to output an instruction input signal to the CPU 60 in response to the user's operation. The lens drive control unit 80 controls the drive of the lenses arranged in the camera block 10, and is configured to control motors (not shown) that drive each lens of the imaging lens 11 based on a control signal from the CPU 60.

The operation of the imaging device 100 will be described below.
In a 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 unit 20 and displayed as a camera-through image. Also, 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 a predetermined lens of the imaging lens 11 moves under the control of the lens drive control unit 80.

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

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

When playing back image data recorded on memory card 1000, specific image data is read out from memory card 1000 by R/W 50 in response to an operation on input unit 70, and after expansion and decoding processing is performed by image processing unit 30, the playback image signal is output to LCD 40 and the playback image is displayed.

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

4. Numerical examples of lenses
Next, specific numerical examples of the zoom lens according to an embodiment of the present disclosure will be described. Here, examples will be described in which specific numerical values are applied to the zoom lenses 1 to 3 according to the configuration examples shown in FIGS.

The meanings of the symbols used in the following tables and explanations are as follows. "Si" indicates the number of the i-th surface, with the numbers increasing from the closest to the object. "ri" indicates the value (mm) of the paraxial radius of curvature of the i-th surface. "di" indicates the value (mm) of the distance on the optical axis between the i-th surface and the i+1-th surface. "ndi" indicates the value of the refractive index 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. "φi" indicates the value (mm) of the effective diameter or aperture diameter of the i-th surface. The part where the value of "ri" is "∞" indicates a flat surface, an aperture surface, etc. "ASP" in the surface number (Si) column indicates that the surface is configured with an aspheric shape. "STO" in the surface number column indicates that the aperture stop (main stop) St is located at the corresponding position. "FC1" in the surface number column indicates that the first flare cutter (first sub-aperture) FC1 is disposed at the corresponding position. "FC2" in the surface number column indicates that the second flare cutter (second sub-aperture) FC2 is disposed at the corresponding position. "OBJ" in the surface number column indicates that the corresponding surface is an object surface. "IMG" in the surface number column indicates that the corresponding surface is an image surface. "f" indicates the focal length of the entire system (unit: mm). "Fno" indicates the open F-number. "ω" indicates the total angle of view (unit: °). "Y" indicates the image height (unit: mm). "L" indicates the total optical length (the distance on the optical axis from the surface closest to the object to the image surface IMG) (unit: mm).

Furthermore, some of the lenses used in the embodiments have aspheric lens surfaces. The aspheric shape is defined by the following formula. In each table showing the aspheric coefficients described below, "E-i" represents an exponential expression with the base 10, that is, "10 ^-i ", and for example, "0.12345E-05" represents "0.12345×10 ^-5 ".

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

[Example 1]
[Table 1] shows basic lens data of the zoom lens 1 according to Example 1 shown in FIG. 1. [Table 2] shows the first surface and focal length (unit: mm) of each group of the zoom lens 1 according to Example 1. [Table 3] shows the values of the focal length f, F value, total angle of view ω, image height Y, and total optical length L of the entire system in the zoom lens 1 according to Example 1. [Table 3] shows values at infinity focusing for each of the wide-angle end (Wide), intermediate focal length (Mid), and telephoto end (Tele). [Table 4] shows data on surface spacing that is variable during zooming in the zoom lens 1 according to Example 1, and data on the effective diameter (aperture diameter) that is variable during zooming. [Table 4] shows values when the object distance (d0) is infinity and when it is close for each of the wide-angle end (Wide), intermediate focal length (Mid), and telephoto end (Tele). Table 5 shows the values of coefficients representing the shape of the aspheric surface in the zoom lens 1 according to the first embodiment.

The zoom lens 1 according to Example 1 includes, in order from the object side to the image surface side, a first lens group GR1, an aperture stop St, a second lens group GR2, and a subsequent group. The subsequent group is made up of a third lens group GR3 and a fourth lens group GR4. The zoom lens 1 according to Example 1 has a four-group configuration as a whole.

In the zoom lens 1 according to Example 1, when zooming from the wide-angle end to the telephoto end, the interval between adjacent lens groups changes along the optical axis Z1. At this time, the first lens group GR1 and the second lens group GR2 move toward the image plane side , and the third lens group GR3 and the fourth lens group GR4 move toward the object side .

When zooming from the wide-angle end to the telephoto end, the distance between the second lens group GR2 and the aperture diaphragm St and the distance between the aperture diaphragm St and the third lens group GR3 also change. In addition, the aperture diaphragm St has a function of cutting out unnecessary light that tends to enter at intermediate image heights by changing its aperture diameter when zooming from the wide-angle end to the telephoto end.

When focusing from infinity to a close distance, the second lens group GR2 moves in the optical axis direction toward the image plane as a focus group.

The first lens group GR1 has negative refractive power overall. The first lens group GR1 is composed of lenses L11 to L14, in order from the object side to the image surface side. Lens L11 is a negative meniscus lens with aspheric surfaces on both sides, with the convex surface facing the object side. Lens L12 is a negative meniscus lens with aspheric surfaces on both sides, with the convex surface facing the object side. Lens L13 is a negative lens with a biconcave shape. Lens L14 is a positive lens with a biconvex shape.

The second lens group GR2 has a negative refractive power as a whole. The second lens group GR2 is composed of a negative lens L21 having aspheric surfaces on both sides.

The third lens group GR3 has positive refractive power overall. The third lens group GR3 is composed of lenses L31 to L33, in that order from the object side to the image surface side. Lenses L31 and L32 are cemented lenses. Lens L31 is a negative meniscus lens with a convex surface facing the object side. Lens L32 is a positive lens with a convex surface facing the object side. Lens L33 is a negative meniscus lens with a concave surface facing the object side.

The first flare cutter FC1 (first secondary aperture) is disposed closest to the image plane of the third lens group GR3. The first flare cutter FC1 has the function of cutting out unwanted light that is likely to enter at intermediate image heights and cannot be cut out by the aperture aperture St alone, as the aperture diameter changes when zooming from the wide-angle end to the telephoto end.

The fourth lens group GR4 has a positive refractive power overall. The fourth lens group GR4 is composed of lenses L41 to L47, in order from the object side to the image side. Lenses L41 and L42 are cemented lenses. Lenses L44 and L45 are cemented lenses. Lens L41 is a negative meniscus lens with a convex surface facing the object side. Lens L42 is a positive lens with a convex surface facing the object side. Lens L43 is a positive biconvex lens with aspheric surfaces on both sides. Lens L44 is a positive lens with a convex surface facing the image side. Lens L45 is a negative biconcave lens. Lens L46 is a negative biconcave lens with aspheric surfaces on both sides. Lens L47 is a positive biconvex lens.

In addition, a second flare cutter FC2 (second secondary aperture) is disposed between lens L43 and lens L44. The second flare cutter FC2 has the function of cutting out unnecessary light that is likely to enter at intermediate image heights and cannot be cut out by the aperture aperture St alone, by changing the aperture diameter when zooming from the wide-angle end to the telephoto end.

The above configuration results in a zoom lens that is wide-angle, yet compact and lightweight, and also has little variation in angle of view or aberration.

Figure 4 shows the longitudinal aberration of the zoom lens 1 according to Example 1 at the wide-angle end and when focusing on infinity. Figure 5 shows the longitudinal aberration of the zoom lens 1 according to Example 1 at the wide-angle end and when focusing on a close distance. Figure 6 shows the longitudinal aberration of the zoom lens 1 according to Example 1 at the intermediate focal length and when focusing on infinity. Figure 7 shows the longitudinal aberration of the zoom lens 1 according to Example 1 at the intermediate focal length and when focusing on a close distance. Figure 8 shows the longitudinal aberration of the zoom lens 1 according to Example 1 at the telephoto end and when focusing on infinity. Figure 9 shows the longitudinal aberration of the zoom lens 1 according to Example 1 at the telephoto end and when focusing on a close distance. Figure 10 shows the lateral aberration of the zoom lens 1 according to Example 1 at the wide-angle end and when focusing on infinity. Figure 11 shows the lateral aberration of the zoom lens 1 according to Example 1 at the wide-angle end and when focusing on a close distance. Figure 12 shows the lateral aberration of the zoom lens 1 according to Example 1 at the intermediate focal length and when focusing on infinity. Fig. 13 shows the lateral aberration of the zoom lens 1 according to Example 1 at an intermediate focal length and when focusing on a close distance. Fig. 14 shows the lateral aberration of the zoom lens 1 according to Example 1 at the telephoto end and when focusing on an infinity object. Fig. 15 shows the lateral aberration of the zoom lens 1 according to Example 1 at the telephoto end and when focusing on a close distance.

As longitudinal aberrations, Figures 4 to 9 show spherical aberration, astigmatism (curvature of field), and distortion. In the spherical aberration diagrams of Figures 4 to 9 and the lateral aberration diagrams of Figures 10 to 15, the solid line shows values at the d-line (587.56 nm), the dashed line shows values at the g-line (435.84 nm), and the dashed line shows values at the C-line (656.27 nm). In the astigmatism diagrams, S shows values at the sagittal image plane, and T shows values at the tangential image plane. In the distortion diagrams, values at the d-line are shown.
The same applies to the aberration diagrams in the other examples that follow.

As can be seen from each aberration diagram, the zoom lens 1 of Example 1 has excellent imaging performance with various aberrations well corrected.

[Example 2]
[Table 6] shows basic lens data of the zoom lens 2 according to Example 2 shown in FIG. 2. [Table 7] shows the first surface and focal length (unit: mm) of each group of the zoom lens 2 according to Example 2. [Table 8] shows the values of the focal length f, F value, total angle of view ω, image height Y, and total optical length L of the entire system in the zoom lens 2 according to Example 2. [Table 8] shows values at infinity focusing for each of the wide-angle end (Wide), intermediate focal length (Mid), and telephoto end (Tele). [Table 9] shows data on surface spacing that is variable during zooming in the zoom lens 2 according to Example 2, and data on the effective diameter (aperture diameter) that is variable during zooming. [Table 9] shows values when the object distance (d0) is infinity and when it is close for each of the wide-angle end (Wide), intermediate focal length (Mid), and telephoto end (Tele). Table 10 shows the values of coefficients representing the shape of the aspheric surface in the zoom lens 2 according to the second embodiment.

The zoom lens 2 according to Example 2 includes, in order from the object side to the image side, a first lens group GR1, an aperture stop St, a second lens group GR2, and a subsequent group. The subsequent group is made up of a third lens group GR3 and a fourth lens group GR4. The zoom lens 2 according to Example 2 has a four-group configuration as a whole.

In the zoom lens 2 according to Example 2, when zooming from the wide-angle end to the telephoto end, the interval between adjacent lens groups changes along the optical axis Z1. At this time, the first lens group GR1 and the second lens group GR2 move toward the image plane side , and the third lens group GR3 and the fourth lens group GR4 move toward the object side .

When zooming from the wide-angle end to the telephoto end, the distance between the second lens group GR2 and the aperture diaphragm St and the distance between the aperture diaphragm St and the third lens group GR3 also change. In addition, the aperture diaphragm St has a function of cutting out unnecessary light that tends to enter at intermediate image heights by changing its aperture diameter when zooming from the wide-angle end to the telephoto end.

When focusing from infinity to a close distance, the second lens group GR2 moves in the optical axis direction toward the image plane as a focus group.

The first lens group GR1 has negative refractive power overall. The first lens group GR1 is composed of lenses L11 to L14, in order from the object side to the image surface side. Lens L11 is a negative meniscus lens with aspheric surfaces on both sides, with the convex surface facing the object side. Lens L12 is a negative meniscus lens with aspheric surfaces on both sides, with the convex surface facing the object side. Lens L13 is a negative lens with a biconcave shape. Lens L14 is a positive lens with a biconvex shape.

The second lens group GR2 has a negative refractive power as a whole. The second lens group GR2 is composed of a negative lens L21 having aspheric surfaces on both sides.

The third lens group GR3 has positive refractive power overall. The third lens group GR3 is composed of lenses L31 to L33, in that order from the object side to the image surface side. Lenses L31 and L32 are cemented lenses. Lens L31 is a negative meniscus lens with a convex surface facing the object side. Lens L32 is a positive lens with a convex surface facing the object side. Lens L33 is a negative meniscus lens with a concave surface facing the object side.

The first flare cutter FC1 (first secondary aperture) is disposed closest to the image plane of the third lens group GR3. The first flare cutter FC1 has the function of cutting out unwanted light that is likely to enter at intermediate image heights and cannot be cut out by the aperture aperture St alone, as the aperture diameter changes when zooming from the wide-angle end to the telephoto end.

The fourth lens group GR4 has a positive refractive power overall. The fourth lens group GR4 is composed of lenses L41 to L47, in order from the object side to the image side. Lenses L41 and L42 are cemented lenses. Lenses L44 and L45 are cemented lenses. Lens L41 is a negative meniscus lens with a convex surface facing the object side. Lens L42 is a positive lens with a convex surface facing the object side. Lens L43 is a positive biconvex lens with aspheric surfaces on both sides. Lens L44 is a positive lens with a convex surface facing the image side. Lens L45 is a negative biconcave lens. Lens L46 is a negative biconcave lens with aspheric surfaces on both sides. Lens L47 is a positive biconvex lens.

In addition, a second flare cutter FC2 (second secondary aperture) is disposed between lens L43 and lens L44. The second flare cutter FC2 has the function of cutting out unnecessary light that is likely to enter at intermediate image heights and cannot be cut out by the aperture aperture St alone, by changing the aperture diameter when zooming from the wide-angle end to the telephoto end.

The above configuration results in a zoom lens that is wide-angle, yet compact and lightweight, and also has little variation in angle of view or aberration.

Figure 16 shows the longitudinal aberration of the zoom lens 2 according to Example 2 at the wide-angle end and when focusing on infinity. Figure 17 shows the longitudinal aberration of the zoom lens 2 according to Example 2 at the wide-angle end and when focusing on a close distance. Figure 18 shows the longitudinal aberration of the zoom lens 2 according to Example 2 at the intermediate focal length and when focusing on infinity. Figure 19 shows the longitudinal aberration of the zoom lens 2 according to Example 2 at the intermediate focal length and when focusing on a close distance. Figure 20 shows the longitudinal aberration of the zoom lens 2 according to Example 2 at the telephoto end and when focusing on infinity. Figure 21 shows the longitudinal aberration of the zoom lens 2 according to Example 2 at the telephoto end and when focusing on a close distance. Figure 22 shows the lateral aberration of the zoom lens 2 according to Example 2 at the wide-angle end and when focusing on infinity. Figure 23 shows the lateral aberration of the zoom lens 2 according to Example 2 at the wide-angle end and when focusing on a close distance. Figure 24 shows the lateral aberration of the zoom lens 2 according to Example 2 at the intermediate focal length and when focusing on infinity. Fig. 25 shows the lateral aberration of the zoom lens 2 according to Example 2 at an intermediate focal length and when focusing on a close distance. Fig. 26 shows the lateral aberration of the zoom lens 2 according to Example 2 at the telephoto end and when focusing on an infinity object. Fig. 27 shows the lateral aberration of the zoom lens 2 according to Example 2 at the telephoto end and when focusing on a close distance.

As can be seen from each aberration diagram, the zoom lens 2 of Example 2 has excellent imaging performance with various aberrations well corrected.

[Example 3]
Table 11 shows basic lens data of the zoom lens 3 according to Example 3 shown in FIG. 3. Table 12 shows the first surface and focal length (unit: mm) of each group of the zoom lens 3 according to Example 3. Table 13 shows the focal length f, F value, total angle of view ω, image height Y, and total optical length L of the entire system of the zoom lens 3 according to Example 3. Table 13 shows values at infinity focusing for each of the wide-angle end (Wide), intermediate focal length (Mid), and telephoto end (Tele). Table 14 shows data on surface spacing that is variable during zooming in the zoom lens 3 according to Example 3, and data on effective diameter (aperture diameter) that is variable during zooming. Table 14 shows values when the object distance (d0) is infinity and when it is close for each of the wide-angle end (Wide), intermediate focal length (Mid), and telephoto end (Tele). Table 15 shows the values of coefficients representing the shape of the aspheric surface in the zoom lens 3 according to the third embodiment.

The zoom lens 3 according to Example 3 includes, in order from the object side to the image surface side, a first lens group GR1, an aperture stop St, a second lens group GR2, and a subsequent group. The subsequent group is made up of a third lens group GR3 and a fourth lens group GR4. The zoom lens 3 according to Example 3 has a four-group configuration as a whole.

In the zoom lens 3 according to Example 3, when zooming from the wide-angle end to the telephoto end, the interval between adjacent lens groups changes along the optical axis Z1. At this time, the first lens group GR1 and the second lens group GR2 move toward the image plane side , and the third lens group GR3 and the fourth lens group GR4 move toward the object side .

The aperture diaphragm St changes its diameter when zooming from the wide-angle end to the telephoto end, cutting out unwanted light that tends to enter at intermediate image heights.

When focusing from infinity to a close distance, the second lens group GR2 moves in the optical axis direction toward the image plane as a focus group.

The first lens group GR1 has negative refractive power overall. The first lens group GR1 is composed of lenses L11 to L14, in order from the object side to the image surface side. Lens L11 is a negative meniscus lens with aspheric surfaces on both sides, with the convex surface facing the object side. Lens L12 is a negative meniscus lens with aspheric surfaces on both sides, with the convex surface facing the object side. Lens L13 is a negative lens with a biconcave shape. Lens L14 is a positive lens with a biconvex shape.

The second lens group GR2 has a negative refractive power as a whole. The second lens group GR2 is composed of a negative lens L21 having aspheric surfaces on both sides.

In addition, a first flare cutter FC1 (first secondary aperture) is disposed between the second lens group GR2 and the aperture diaphragm St. The first flare cutter FC1 has the function of cutting out unnecessary light that tends to enter at intermediate image heights and cannot be cut out by the aperture diaphragm St alone, as the aperture diameter changes when zooming from the wide-angle end to the telephoto end.

The third lens group GR3 has positive refractive power overall. The third lens group GR3 is composed of lenses L31 to L33, in that order from the object side to the image surface side. Lenses L31 and L32 are cemented lenses. Lens L31 is a negative meniscus lens with a convex surface facing the object side. Lens L32 is a positive lens with a convex surface facing the object side. Lens L33 is a negative meniscus lens with a concave surface facing the object side.

In addition, the second flare cutter FC2 (second secondary aperture) is disposed closest to the image plane of the third lens group GR3. The second flare cutter FC2 has the function of cutting out unwanted light that is likely to enter at intermediate image heights and cannot be cut out by the aperture aperture St alone, by changing the aperture diameter when zooming from the wide-angle end to the telephoto end.

The fourth lens group GR4 has a positive refractive power overall. The fourth lens group GR4 is composed of lenses L41 to L47, in order from the object side to the image side. Lenses L41 and L42 are cemented lenses. Lenses L44 and L45 are cemented lenses. Lens L41 is a negative meniscus lens with a convex surface facing the object side. Lens L42 is a positive lens with a convex surface facing the object side. Lens L43 is a positive biconvex lens with aspheric surfaces on both sides. Lens L44 is a positive lens with a convex surface facing the image side. Lens L45 is a negative biconcave lens. Lens L46 is a negative lens with aspheric surfaces on both sides. Lens L47 is a positive biconvex lens.

The above configuration results in a zoom lens that is wide-angle, yet compact and lightweight, and also has little variation in angle of view or aberration.

Figure 28 shows the longitudinal aberration of the zoom lens 3 according to Example 3 at the wide-angle end and when focusing on infinity. Figure 29 shows the longitudinal aberration of the zoom lens 3 according to Example 3 at the wide-angle end and when focusing on a close distance. Figure 30 shows the longitudinal aberration of the zoom lens 3 according to Example 3 at the intermediate focal length and when focusing on infinity. Figure 31 shows the longitudinal aberration of the zoom lens 3 according to Example 3 at the intermediate focal length and when focusing on a close distance. Figure 32 shows the longitudinal aberration of the zoom lens 3 according to Example 3 at the telephoto end and when focusing on infinity. Figure 33 shows the longitudinal aberration of the zoom lens 3 according to Example 3 at the telephoto end and when focusing on a close distance. Figure 34 shows the lateral aberration of the zoom lens 3 according to Example 3 at the wide-angle end and when focusing on infinity. Figure 35 shows the lateral aberration of the zoom lens 3 according to Example 3 at the wide-angle end and when focusing on a close distance. Figure 36 shows the lateral aberration of the zoom lens 3 according to Example 3 at the intermediate focal length and when focusing on infinity. Fig. 37 shows the lateral aberration of the zoom lens 3 according to Example 3 at an intermediate focal length and when focusing on a close distance. Fig. 38 shows the lateral aberration of the zoom lens 3 according to Example 3 at the telephoto end and when focusing on an infinity object. Fig. 39 shows the lateral aberration of the zoom lens 3 according to Example 3 at the telephoto end and when focusing on a close distance.

As can be seen from each aberration diagram, the zoom lens 3 of Example 3 has excellent imaging performance with various aberrations well corrected.

[Other numerical data for each embodiment]
Table 16 shows the values for each of the above conditional expressions for each embodiment. As can be seen from Table 16, the values for each embodiment are within the numerical range for each conditional expression.

<5. Application Examples>
[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 may be realized as a device mounted on any type of moving body, such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, a personal mobility device, an airplane, a drone, a ship, a robot, a construction machine, or an agricultural machine (tractor).

FIG. 41 is a block diagram showing a schematic configuration example of a vehicle control system 7000, which is an example of a mobile body control system to which the technology disclosed herein can be applied. The vehicle control system 7000 includes a plurality of electronic control units connected via a communication network 7010. In the example shown in FIG. 41, 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 vehicle information detection unit 7400, an inside vehicle information detection unit 7500, and an integrated control unit 7600. The communication network 7010 connecting these multiple control units may be, for example, an in-vehicle communication network conforming to any standard such as CAN (Controller Area Network), LIN (Local Interconnect Network), LAN (Local Area Network), or FlexRay (registered trademark).

Each control unit includes a microcomputer that performs arithmetic processing according to various programs, a storage unit that stores the programs executed by the microcomputer or parameters used in various calculations, and a drive circuit that drives various control target devices. Each control unit includes a network I/F for communicating with other control units via a communication network 7010, and a communication I/F for communicating with devices or sensors inside and outside the vehicle by wired or wireless communication. In FIG. 41, 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 device I/F 7660, an audio/image output unit 7670, an in-vehicle network I/F 7680, and a storage unit 7690. Other control units also include a microcomputer, a communication I/F, a storage unit, and the like.

The drivetrain control unit 7100 controls the operation of devices related to the drivetrain of the vehicle according to various programs. For example, the drivetrain control unit 7100 functions as a control device for a drive force generating device for generating a drive force of the vehicle, such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, and a braking device for generating a braking force of the vehicle. The drivetrain control unit 7100 may also function as a control device such as an ABS (Antilock Brake System) or an ESC (Electronic Stability Control).

A vehicle state detection unit 7110 is connected to the drive system control unit 7100. The vehicle state detection unit 7110 includes at least one of 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, or a sensor for detecting the amount of operation of the accelerator pedal, the amount of operation of the brake pedal, the steering angle of the steering wheel, the engine speed, or the rotation speed of the wheels, for example. The drive system control unit 7100 performs arithmetic processing using signals input from the vehicle state detection unit 7110, and controls the internal combustion engine, the drive motor, the electric power steering device, the brake device, etc.

The body system control unit 7200 controls the operation of various devices installed in the vehicle body according to various programs. For example, the body system control unit 7200 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as headlamps, tail lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves or signals from various switches transmitted from a portable device that replaces a key can be input to the body system control unit 7200. The body system control unit 7200 accepts the input of these radio waves or signals and controls the vehicle's door lock device, power window device, lamps, etc.

The battery control unit 7300 controls the secondary battery 7310, which is the power supply source for the drive motor, according to various programs. For example, information such as battery temperature, battery output voltage, or remaining capacity of the battery is input to the battery control unit 7300 from a battery device equipped with the secondary battery 7310. The battery control unit 7300 performs calculations using these signals, and controls the temperature regulation of the secondary battery 7310 or a cooling device or the like equipped in the battery device.

The outside-vehicle information detection unit 7400 detects information outside the vehicle equipped with the vehicle control system 7000. For example, at least one of the imaging unit 7410 and the outside-vehicle information detection unit 7420 is connected to the outside-vehicle 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 outside-vehicle information detection unit 7420 includes, for example, an environmental sensor for detecting the current weather or climate, or at least one of surrounding information detection sensors for detecting other vehicles, obstacles, pedestrians, etc. around the vehicle equipped with the vehicle control system 7000.

The environmental sensor may be, for example, at least one of a raindrop sensor that detects rain, a fog sensor that detects fog, a sunshine sensor that detects the degree of sunshine, and a snow sensor that detects snowfall. The surrounding 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. The imaging unit 7410 and the outside vehicle information detection unit 7420 may each be provided as an independent sensor or device, or may be provided as a device in which multiple sensors or devices are integrated.

Here, FIG. 42 shows an example of the installation positions of the imaging unit 7410 and the outside vehicle 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 the upper part of the windshield inside the vehicle cabin of the vehicle 7900. The imaging unit 7910 provided on the front nose and the imaging unit 7918 provided on the upper part of the windshield inside the vehicle cabin mainly acquire images of the front of the vehicle 7900. The imaging units 7912 and 7914 provided on the side mirrors mainly acquire images of the sides of the vehicle 7900. The imaging unit 7916 provided on the rear bumper or back door mainly acquires images of the rear of the vehicle 7900. The imaging unit 7918 provided on the upper part of the windshield inside the vehicle cabin is mainly used to detect preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, lanes, etc.

Figure 42 shows an example of the imaging ranges of each of the imaging units 7910, 7912, 7914, and 7916. Imaging range a indicates the imaging range of the imaging unit 7910 provided on the front nose, imaging ranges b and c indicate the imaging ranges of the imaging units 7912 and 7914 provided on the side mirrors, respectively, and imaging range d indicates the imaging range of the imaging unit 7916 provided on the rear bumper or back door. For example, image data captured by the imaging units 7910, 7912, 7914, and 7916 are superimposed to obtain an overhead image of the vehicle 7900 viewed from above.

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

Returning to FIG. 41, the explanation will be continued. The outside-vehicle information detection unit 7400 causes the imaging unit 7410 to capture an image outside the vehicle and receives the captured image data. The outside-vehicle information detection unit 7400 also receives detection information from the connected outside-vehicle information detection unit 7420. When the outside-vehicle information detection unit 7420 is an ultrasonic sensor, a radar device, or a LIDAR device, the outside-vehicle information detection unit 7400 transmits ultrasonic waves or electromagnetic waves, and receives information on the received reflected waves. The outside-vehicle information detection unit 7400 may perform object detection processing or distance detection processing for people, cars, obstacles, signs, or characters on the road surface, based on the received information. The outside-vehicle information detection unit 7400 may perform environmental recognition processing for recognizing rainfall, fog, road conditions, etc., based on the received information. The outside-vehicle information detection unit 7400 may calculate the distance to an object outside the vehicle based on the received information.

The outside vehicle information detection unit 7400 may also perform image recognition processing or distance detection processing to recognize people, cars, obstacles, signs, or characters on the road surface, based on the received image data. The outside vehicle information detection unit 7400 may perform processing such as distortion correction or alignment on the received image data, and may also generate an overhead image or a panoramic image by synthesizing image data captured by different imaging units 7410. The outside vehicle information detection unit 7400 may also perform viewpoint conversion processing using image data captured by different imaging units 7410.

The in-vehicle information detection unit 7500 detects information inside the vehicle. For example, a driver state detection unit 7510 that detects the state of the driver is connected to the in-vehicle information detection unit 7500. The driver state detection unit 7510 may include a camera that captures an image of the driver, a biosensor that detects the driver's biometric information, or a microphone that collects sound inside the vehicle. The biosensor is provided, for example, on the seat or steering wheel, and detects the biometric information of a passenger sitting in the seat or a driver holding the 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, or may determine whether the driver is dozing. The in-vehicle information detection unit 7500 may perform processing such as noise canceling processing on the collected sound signal.

The integrated control unit 7600 controls the overall operation of the vehicle control system 7000 according to various programs. The input unit 7800 is connected to the integrated control unit 7600. The input unit 7800 is realized by a device that can be operated by the passenger, such as a touch panel, a button, a microphone, a switch, or a lever. Data obtained by voice recognition of a voice input by a microphone may be input to the integrated control unit 7600. The input unit 7800 may be, for example, a remote control device using infrared or other radio waves, or an external connection device such as a mobile phone or a PDA (Personal Digital Assistant) that supports the operation of the vehicle control system 7000. The input unit 7800 may be, for example, a camera, in which case the passenger can input information by gestures. Alternatively, data obtained by detecting the movement of a wearable device worn by the passenger may be input. Furthermore, the input unit 7800 may include, for example, an input control circuit that generates an input signal based on information input by the passenger using the above-mentioned input unit 7800 and outputs the input signal to the integrated control unit 7600. Passengers and the like can operate this input unit 7800 to input various data to the vehicle control system 7000 and to 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, etc. The storage unit 7690 may also be realized by a magnetic storage device such as a hard disk drive (HDD), a semiconductor storage device, an optical storage device, or a magneto-optical storage device.

The general-purpose communication I/F 7620 is a general-purpose communication I/F that mediates communication between various devices present in the external environment 7750. The general-purpose communication I/F 7620 may implement cellular communication protocols 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 called Wi-Fi (registered trademark)) and Bluetooth (registered trademark). The general-purpose communication I/F 7620 may connect to devices (e.g., application servers or control servers) present on an external network (e.g., the Internet, a cloud network, or an operator-specific network) via, for example, a base station or an access point. In addition, the general-purpose communication I/F 7620 may connect to a terminal located in the vicinity of the vehicle (e.g., a terminal of a driver, pedestrian, or store, or an MTC (Machine Type Communication) terminal) using, for example, P2P (Peer To Peer) technology.

The dedicated communication I/F 7630 is a communication I/F that supports a communication protocol developed for use in a vehicle. The dedicated communication I/F 7630 may implement a standard protocol such as WAVE (Wireless Access in Vehicle Environment), DSRC (Dedicated Short Range Communications), or a cellular communication protocol, which is a combination of a lower layer IEEE 802.11p and a higher layer IEEE 1609. The dedicated communication I/F 7630 typically performs V2X communication, which is a concept including one or more of vehicle-to-vehicle communication, vehicle-to-infrastructure communication, vehicle-to-home communication, and vehicle-to-pedestrian communication.

The positioning unit 7640 performs positioning by receiving, for example, a GNSS signal from a Global Navigation Satellite System (GNSS) satellite (for example, a GPS signal from a Global Positioning System (GPS) satellite), and generates position information including the latitude, longitude, and altitude of the vehicle. The positioning unit 7640 may determine the current position by exchanging signals with a wireless access point, or may obtain position information from a terminal such as a mobile phone, PHS, or smartphone that has a positioning function.

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

The in-vehicle device I/F 7660 is a communication interface that mediates the connection between the microcomputer 7610 and various in-vehicle devices 7760 present in the vehicle. The in-vehicle device I/F 7660 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). The in-vehicle device I/F 7660 may also establish a wired connection such as USB (Universal Serial Bus), HDMI (registered trademark) (High-Definition Multimedia Interface), or MHL (Mobile High-definition Link) via a connection terminal (and a cable, if necessary) not shown. The in-vehicle device 7760 may include at least one of a mobile device or wearable device owned by a passenger, or an information device carried into or attached to a vehicle. The in-vehicle device 7760 may also include a navigation device that searches for a route to an arbitrary destination. The in-vehicle equipment I/F 7660 exchanges control signals or data signals with these in-vehicle equipment 7760.

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

The microcomputer 7610 of the integrated control unit 7600 controls the vehicle control system 7000 according to various programs based on information acquired through at least one of the general-purpose communication I/F 7620, the dedicated communication I/F 7630, the positioning unit 7640, the beacon receiving unit 7650, the in-vehicle device I/F 7660, and the in-vehicle network I/F 7680. For example, the microcomputer 7610 may calculate the control target value of the driving force generating device, the steering mechanism, or the braking device based on the acquired information inside and outside the vehicle, and output a control command to the drive system control unit 7100. For example, the microcomputer 7610 may perform cooperative control for the purpose of realizing the functions of an ADAS (Advanced Driver Assistance System), including vehicle collision avoidance or impact mitigation, following driving based on the distance between vehicles, vehicle speed maintenance driving, vehicle collision warning, vehicle lane departure warning, etc. In addition, the microcomputer 7610 may perform cooperative control for the purpose of autonomous driving, in which the vehicle travels autonomously without relying on driver operation, by controlling a driving force generating device, a steering mechanism, a braking device, etc. based on information acquired about the vehicle's surroundings.

The microcomputer 7610 may generate three-dimensional distance information between the vehicle and objects such as surrounding structures and people based on information acquired through at least one of the general-purpose communication I/F 7620, the dedicated communication I/F 7630, the positioning unit 7640, the beacon receiving unit 7650, the in-vehicle device I/F 7660, and the in-vehicle network I/F 7680, and may create local map information including information about the surroundings of the current position of the vehicle. The microcomputer 7610 may also predict dangers such as vehicle collisions, the approach of pedestrians, or entry into closed roads based on the acquired information, and generate warning signals. The warning signals may be, for example, signals for generating warning sounds or turning on warning lamps.

The audio/image output unit 7670 transmits at least one of audio and image output signals to an output device capable of visually or audibly notifying the passengers of the vehicle or the outside of the vehicle of information. In the example of FIG. 41, an audio speaker 7710, a display unit 7720, and an instrument panel 7730 are illustrated as output devices. The display unit 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. The output device may be other devices such as headphones, a wearable device such as a glasses-type display worn by the passenger, a projector, or a lamp other than these devices. When the output device is a display device, the display device visually displays the results obtained by various processes performed by the microcomputer 7610 or information received from other control units in various formats such as text, images, tables, graphs, etc. When the output device is an audio output device, the audio output device converts an audio signal consisting of reproduced audio data or acoustic data into an analog signal and audibly outputs it.

In the example shown in FIG. 41, at least two control units connected via the communication network 7010 may be integrated into one control unit. Alternatively, each control unit may be composed of multiple control units. Furthermore, the vehicle control system 7000 may include another control unit not shown. In addition, in the above description, some or all of the functions performed by any control unit may be provided by another control unit. In other words, as long as information is transmitted and received via the communication network 7010, a predetermined calculation process may be performed by any control unit. Similarly, a sensor or device connected to any control unit may be connected to another control unit, and multiple control units may transmit and receive detection information to each other via the communication network 7010.

In the vehicle control system 7000 described above, the zoom 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 disclosed herein may be applied to an endoscopic surgery system.

Figure 43 is a diagram showing an example of a schematic configuration of an endoscopic surgery system 5000 to which the technology disclosed herein can be applied. Figure 43 shows an operator (doctor) 5067 performing surgery on a patient 5071 on a patient bed 5069 using the endoscopic surgery system 5000. As shown in the figure, the endoscopic surgery system 5000 is composed of an endoscope 5001, other surgical tools 5017, a support arm device 5027 that supports the endoscope 5001, and a cart 5037 on which various devices for endoscopic surgery are mounted.

In endoscopic surgery, instead of cutting the abdominal wall to open the abdomen, multiple cylindrical opening instruments called trocars 5025a to 5025d are punctured into the abdominal wall. Then, the endoscope barrel 5003 of the endoscope 5001 and other surgical tools 5017 are inserted into the body cavity of the patient 5071 from the trocars 5025a to 5025d. In the illustrated example, the other surgical tools 5017 include an insufflation tube 5019, an energy treatment tool 5021, and forceps 5023, which are inserted into the body cavity of the patient 5071. The energy treatment tool 5021 is a treatment tool that uses high-frequency current or ultrasonic vibration to incise and peel tissue, or seal blood vessels. However, the illustrated surgical tool 5017 is merely an example, and various surgical tools generally used in endoscopic surgery, such as a trocar or retractor, may be used as the surgical tool 5017.

An image of the surgical site in the body cavity of the patient 5071 captured by the endoscope 5001 is displayed on the display device 5041. The surgeon 5067 performs treatment such as resecting the affected area using the energy treatment tool 5021 and forceps 5023 while viewing the image of the surgical site displayed on the display device 5041 in real time. Although not shown in the figure, the pneumoperitoneum tube 5019, the energy treatment tool 5021, and the forceps 5023 are supported by the surgeon 5067 or an assistant during surgery.

(Support arm device)
The support arm device 5027 includes an arm portion 5031 extending from a base portion 5029. In the example shown, the arm portion 5031 is composed of joint portions 5033a, 5033b, and 5033c and links 5035a and 5035b, and is driven under the control of an arm control device 5045. The arm portion 5031 supports the endoscope 5001, and controls its position and attitude. This allows the endoscope 5001 to be stably fixed in position.

(Endoscopy)
The endoscope 5001 is composed of a lens barrel 5003, a region of a predetermined length from the tip of which is inserted into a body cavity of a patient 5071, and a camera head 5005 connected to the base end of the lens barrel 5003. In the illustrated example, the endoscope 5001 is configured as a so-called rigid lens barrel having a rigid lens barrel 5003, but the endoscope 5001 may be configured as a so-called flexible lens barrel having a flexible lens barrel 5003.

An opening into which an objective lens is fitted is provided at the tip of the lens barrel 5003. 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 by a light guide extending inside the lens barrel 5003, and is irradiated via the objective lens toward an observation target in the body cavity of the patient 5071. The endoscope 5001 may be a direct-viewing endoscope, an oblique-viewing endoscope, or a side-viewing endoscope.

An optical system and an image sensor are provided inside the camera head 5005, and reflected light (observation light) from the object of observation is focused on the image sensor by the optical system. The image sensor converts the observation light photoelectrically to generate an electrical signal corresponding to the observation light, i.e., an image signal corresponding to the observed image. The image signal is transmitted to a camera control unit (CCU) 5039 as RAW data. The camera head 5005 is equipped with a function for adjusting the magnification and focal length by appropriately driving the optical system.

In addition, in order to support, for example, stereoscopic vision (3D display), the camera head 5005 may be provided with multiple image pickup elements. In this case, multiple relay optical systems are provided inside the lens barrel 5003 to guide observation light to each of the multiple image pickup elements.

(Various devices mounted on the cart)
The CCU 5039 is configured with a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), etc., and performs overall control of the operations of the endoscope 5001 and the display device 5041. Specifically, the CCU 5039 performs various image processing, such as development processing (demosaic processing), on the image signal received from the camera head 5005 in order to display an image based on the image signal. The CCU 5039 provides the image signal that has been subjected to the image processing to the display device 5041. The CCU 5039 also transmits a control signal to the camera head 5005 to control its drive. The control signal may include information on imaging conditions, such as magnification and focal length.

The display device 5041 displays an image based on an image signal that has been subjected to image processing by the CCU 5039 under the control of the CCU 5039. If the endoscope 5001 is compatible with high-resolution imaging such as 4K (3840 horizontal pixels x 2160 vertical pixels) or 8K (7680 horizontal pixels x 4320 vertical pixels) and/or compatible with 3D display, the display device 5041 may be capable of displaying high resolution and/or 3D display, respectively. If the endoscope 5001 is compatible with high-resolution imaging such as 4K or 8K, a display device 5041 with a size of 55 inches or more can be used to provide a more immersive experience. In addition, multiple display devices 5041 with 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) and supplies illumination light to the endoscope 5001 when photographing the surgical site.

The arm control device 5045 is configured by a processor such as a CPU, and operates according to a predetermined program to control the drive 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. The user can input various information and instructions to the endoscopic surgery system 5000 via the input device 5047. For example, the user inputs various information related to the surgery, such as the patient's physical information and information about the surgical procedure, via the input device 5047. In addition, for example, the user inputs, via the input device 5047, an instruction to drive the arm portion 5031, an instruction to change the imaging conditions (type of irradiation light, magnification, focal length, etc.) of the endoscope 5001, an instruction to drive the energy treatment tool 5021, etc.

The type of the input device 5047 is not limited, and the input device 5047 may be any known input device. For example, a mouse, a keyboard, a touch panel, a switch, a foot switch 5057, and/or a lever may be used as the input device 5047. 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 glasses-type wearable device or an HMD (Head Mounted Display), and various inputs are made according to the user's gestures and gaze detected by these devices. The input device 5047 also includes a camera capable of detecting the user's movements, and various inputs are made according to the user's gestures and gaze detected from the image captured by the camera. Furthermore, the input device 5047 includes a microphone capable of picking up the user's voice, and various inputs are made by voice via the microphone. In this way, the input device 5047 is configured to be able to input various information in a non-contact manner, which makes it possible for a user (e.g., the surgeon 5067) who belongs to a clean area to operate equipment in a non-clean area in a non-contact manner. In addition, the user can operate the equipment without taking his or her hands off the surgical tool he or she is holding, improving the user's convenience.

The treatment tool control device 5049 controls the operation of the energy treatment tool 5021 for cauterizing tissue, incising, sealing blood vessels, etc. The insufflation device 5051 sends gas into the body cavity of the patient 5071 via the insufflation tube 5019 to inflate the body cavity in order to ensure the field of view of the endoscope 5001 and to ensure the working space of the surgeon. The recorder 5053 is a device capable of recording various information related to the surgery. The printer 5055 is a device capable of printing various information related to the surgery in various formats such as text, images, or graphs.

Below, the particularly characteristic configurations of the endoscopic surgery system 5000 are described in further detail.

(Support arm device)
The support arm device 5027 includes a base 5029, which is a base, and an arm 5031 extending from the base 5029. In the illustrated example, the arm 5031 is composed of a plurality of joints 5033a, 5033b, and 5033c, and a plurality of links 5035a and 5035b connected by the joint 5033b. However, in FIG. 43, for the sake of simplicity, the configuration of the arm 5031 is simplified. In reality, the shape, number, and arrangement of the joints 5033a to 5033c and the links 5035a and 5035b, as well as the direction of the rotation axis of the joints 5033a to 5033c, can be appropriately set so that the arm 5031 has a desired degree of freedom. For example, the arm 5031 can be preferably configured to have six or more degrees of freedom. This makes it possible to freely move the endoscope 5001 within the movable range of the arm portion 5031, making it possible to insert the lens barrel 5003 of the endoscope 5001 into the body cavity of the patient 5071 from the desired direction.

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. The drive of the actuators is controlled by the arm control device 5045, thereby controlling the rotation angle of each joint 5033a to 5033c and controlling the drive of the arm unit 5031. This makes it possible to control the position and attitude of the endoscope 5001. At this time, the arm control device 5045 can control the drive of the arm unit 5031 by various known control methods, such as force control or position control.

For example, the surgeon 5067 may perform appropriate operation input via the input device 5047 (including the foot switch 5057), and the drive of the arm unit 5031 may be appropriately controlled by the arm control device 5045 in response to the operation input, thereby controlling the position and posture of the endoscope 5001. Through this control, the endoscope 5001 at the tip of the arm unit 5031 may be moved from any position to any position, and then fixedly supported at the position after the movement. The arm unit 5031 may be operated in a so-called master-slave manner. In this case, the arm unit 5031 may be remotely operated by the user via the input device 5047 installed in a location away from the operating room.

In addition, when force control is applied, the arm control device 5045 may perform so-called power assist control in which the actuators of the joints 5033a to 5033c are driven so that the arm unit 5031 receives an external force from the user and moves smoothly in accordance with the external force. This allows the arm unit 5031 to be moved with a relatively light force when the user moves the arm unit 5031 while directly touching it. This makes it possible to move the endoscope 5001 more intuitively and with simpler operations, improving user convenience.

Generally, in endoscopic surgery, the endoscope 5001 is supported by a doctor called a scopist. By using the support arm device 5027, the position of the endoscope 5001 can be fixed more reliably without relying on human hands, so images of the surgical site can be obtained stably and the surgery can be performed smoothly.

The arm control device 5045 does not necessarily have to be provided on the cart 5037. Furthermore, the arm control device 5045 does not necessarily have to be a single device. For example, the arm control device 5045 may be provided on each of the joints 5033a to 5033c of the arm section 5031 of the support arm device 5027, and drive control of the arm section 5031 may be achieved by multiple arm control devices 5045 working together.

(Light source device)
The light source device 5043 supplies the endoscope 5001 with irradiation light for photographing the surgical site. The light source device 5043 is composed of a white light source composed of, for example, an LED, a laser light source, or a combination of these. In this case, when the white light source is composed of a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high precision, so that the light source device 5043 can adjust the white balance of the captured image. In this case, it is also possible to time-share images corresponding to each of RGB by irradiating the observation target with laser light from each of the RGB laser light sources and controlling the driving of the image sensor of the camera head 5005 in synchronization with the irradiation timing. According to this method, a color image can be obtained without providing a color filter to the image sensor.

In addition, the light source device 5043 may be controlled to change the intensity of the light it outputs at predetermined time intervals. The driving of the image sensor of the camera head 5005 is controlled in synchronization with the timing of the change in the light intensity to acquire images in a time-division manner, and the images are then synthesized to generate an image with a high dynamic range that is free of so-called blackout and whiteout.

The light source device 5043 may also be configured to supply light of a predetermined wavelength band corresponding to the special light observation. In the special light observation, for example, by utilizing the wavelength dependency of light absorption in body tissue, a narrow band light is irradiated compared to the irradiation light (i.e., white light) during normal observation, and a predetermined tissue such as blood vessels on the mucosal surface is photographed with high contrast, so-called narrow band imaging is performed. Alternatively, in the special light observation, a fluorescent observation may be performed in which an image is obtained by fluorescence generated by irradiating excitation light. In the fluorescent observation, excitation light is irradiated to the body tissue and the fluorescence from the body tissue is observed (autofluorescence observation), or a reagent such as indocyanine green (ICG) is locally injected into the body tissue and excitation light corresponding to the fluorescent wavelength of the reagent is irradiated to the body tissue to obtain a fluorescent image. The light source device 5043 may be configured to supply narrow band light and/or excitation light corresponding to such special light observation.

(Camera head and CCU)
The functions of the camera head 5005 and the CCU 5039 of the endoscope 5001 will be described in more detail with reference to Fig. 44. Fig. 44 is a block diagram showing an example of the functional configuration of the camera head 5005 and the CCU 5039 shown in Fig. 43.

Referring to Fig. 44, the camera head 5005 has, as its functions, a lens unit 5007, an imaging unit 5009, a drive unit 5011, a communication unit 5013, and a camera head control unit 5015. The CCU 5039 has, as its functions, a communication unit 5059, an image processing unit 5061, and a control unit 5063. The camera head 5005 and the CCU 5039 are connected by a transmission cable 5065 so as to be able to communicate in both directions.

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

The imaging unit 5009 is composed of an imaging element and is arranged after the lens unit 5007. The observation light that passes through the lens unit 5007 is focused on the light receiving surface of the imaging element, and an image signal corresponding to the observation image is generated by photoelectric conversion. The image signal generated by the imaging unit 5009 is provided to the communication unit 5013.

The imaging element constituting the imaging unit 5009 is, for example, a CMOS (Complementary Metal Oxide Semiconductor) type image sensor capable of color imaging with a Bayer array. The imaging element may be capable of capturing high-resolution images of, for example, 4K or higher. Obtaining a high-resolution image of the surgical site allows the surgeon 5067 to grasp the state of the surgical site in more detail, enabling the surgery to proceed more smoothly.

The imaging element constituting the imaging unit 5009 is configured to have a pair of imaging elements for acquiring image signals for the right eye and the left eye corresponding to 3D display. The 3D display allows the surgeon 5067 to more accurately grasp the depth of the biological tissue in the surgical site. When the imaging unit 5009 is configured as a multi-plate type, multiple lens units 5007 are also provided corresponding to the respective imaging elements.

Furthermore, 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 composed of an actuator, and moves the zoom lens and focus lens of the lens unit 5007 a predetermined distance along the optical axis under the control of the camera head control unit 5015. This allows the magnification and focus of the image captured by the imaging unit 5009 to be appropriately adjusted.

The communication unit 5013 is composed of a communication device for transmitting and receiving various information to and from the 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, in order to display the captured image of the surgical site with low latency, it is preferable that the image signal is transmitted by optical communication. During surgery, the surgeon 5067 performs surgery while observing the condition of the affected area using the captured image, so that a moving image of the surgical site is required to be displayed as quickly as possible in real time for a safer and more reliable surgery. 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. The image signal is converted into an optical signal by the photoelectric conversion module and then transmitted to the CCU 5039 via the transmission cable 5065.

The communication unit 5013 also receives a control signal from the CCU 5039 for controlling the operation of the camera head 5005. The control signal includes information on the imaging conditions, such as information specifying the frame rate of the captured image, information specifying the exposure value at the time of capturing an image, and/or information specifying the magnification and focus of the captured image. The communication unit 5013 provides the received control signal to the camera head control unit 5015. 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 converted into an electrical signal by the photoelectric conversion module and then provided to the camera head control unit 5015.

The above-mentioned frame rate, exposure value, magnification, focus, and other imaging conditions are automatically set by the control unit 5063 of the CCU 5039 based on the acquired image signal. In other words, 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 the driving of the camera head 5005 based on a control signal from the CCU 5039 received via the communication unit 5013. For example, the camera head control unit 5015 controls the driving of the image sensor of the imaging unit 5009 based on information specifying the frame rate of the captured image and/or information specifying the exposure during imaging. Also, for example, the camera head control unit 5015 appropriately moves the zoom lens and focus lens of the lens unit 5007 via the drive unit 5011 based on information specifying the magnification and focus of the captured image. The camera head control unit 5015 may further include a function for storing information for identifying the lens barrel 5003 and the camera head 5005.

In addition, by arranging components such as the lens unit 5007 and the imaging unit 5009 within a sealed structure that is highly airtight and waterproof, the camera head 5005 can be made resistant to autoclave sterilization processing.

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

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

The 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 various known signal processing such as development processing, high image quality processing (band enhancement processing, super-resolution processing, NR (Noise reduction) processing, and/or image stabilization processing, etc.), and/or enlargement processing (electronic zoom processing). The image processing unit 5061 also performs detection processing on the image signal to perform AE, AF, and AWB.

The image processing unit 5061 is configured with a processor such as a CPU or a GPU, and the above-mentioned image processing and detection processing can be performed by the processor operating according to a predetermined program. When the image processing unit 5061 is configured with multiple GPUs, the image processing unit 5061 appropriately divides information related to the image signal and performs image processing in parallel using these multiple 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 a control signal for controlling the driving of the camera head 5005. At this time, if the imaging conditions have been input by the user, the control unit 5063 generates a control signal based on the input by the user. Alternatively, if the endoscope 5001 is equipped with an AE function, an AF function, and an AWB function, the control unit 5063 appropriately calculates the optimal exposure value, focal length, and white balance according to the results of the detection processing by the image processing unit 5061, and generates a control signal.

In addition, the control unit 5063 causes the display device 5041 to display an image of the surgical site based on the image signal that has been image-processed by the image processing unit 5061. At this time, the control unit 5063 uses various image recognition techniques to recognize various objects in the surgical site image. For example, the control unit 5063 can recognize surgical tools such as forceps, specific biological parts, bleeding, mist when using the energy treatment tool 5021, and the like, by detecting the shape and color of the edges of objects contained in the surgical site image. When the control unit 5063 causes the display device 5041 to display an image of the surgical site, it uses the recognition result to superimpose various types of surgical support information on the image of the surgical site. The surgical support information is superimposed and presented to the surgeon 5067, making it possible to proceed with the surgery more safely and reliably.

The transmission cable 5065 connecting the camera head 5005 and the CCU 5039 is an electrical signal cable corresponding to communication of electrical signals, an optical fiber corresponding to optical communication, or a composite cable of these.

In the illustrated example, communication is performed wired using the transmission cable 5065, but communication between the camera head 5005 and the CCU 5039 may be performed wirelessly. When communication between the two is performed wirelessly, there is no need to lay the transmission cable 5065 in the operating room, which can eliminate the situation in which the transmission cable 5065 impedes the movement of medical staff in the operating room.

The above describes an example of an endoscopic surgery system 5000 to which the technology disclosed herein can be applied. Note that, although the endoscopic surgery system 5000 has been described here as an example, systems to which the technology disclosed herein can be applied are not limited to such an example. For example, the technology disclosed herein may be applied to a flexible endoscope system for inspection or a microsurgery system.

The technology disclosed herein may be suitably applied to the camera head 5005 of the configurations described above. In particular, the zoom lens disclosed herein may 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 above-described embodiment and examples, and various modifications are possible.

For example, the shapes and numerical values of each part shown in the above embodiment and examples are merely examples of specific embodiments for implementing this technology, and should not be interpreted in a limiting manner to the technical scope of this technology.

In addition, in the above embodiment and example, a configuration substantially consisting of four lens groups as a whole has been described, but a configuration substantially consisting of three, five or more lens groups as a whole may also be used. Furthermore, a configuration further including a lens that has substantially no refractive power may also be used.

For example, the present technology can be configured as follows.
According to the present technology having the following configuration, a zoom lens and an image pickup device can be realized that are configured with three or more lens groups overall and have an optimized configuration for each lens group, thereby enabling smooth focusing operations while minimizing fluctuations in the angle of view and aberrations during focusing.

[1]
From the object side to the image plane side,
a first lens group having a negative meniscus lens with a convex surface facing the object side and having negative refractive power,
a second lens group having negative refractive power and moving toward the image surface side during focusing;
The aperture stop as the main aperture,
and a subsequent group including at least one lens group having a positive refractive power;
A zoom lens in which the spacing between adjacent lens groups changes when zooming from the wide-angle end to the telephoto end, and the following condition is satisfied:
0.2<f1/f2<0.9...(1)
however,
f1: focal length of the first lens group, and f2: focal length of the second lens group.
[2]
The zoom lens according to the above-mentioned [1], wherein the first lens group has a positive lens arranged closer to an image plane than the negative meniscus lens.
[3]
The zoom lens according to the above-mentioned [1] or [2], wherein the second lens group is composed of a single lens component.
[4]
The zoom lens according to any one of the above [1] to [3], which satisfies the following conditional expression:
0.7<Bfw/fw<1.4...(2)
however,
Bfw: back focus at the wide-angle end fw: focal length of the entire system at the wide-angle end.
[5]
The zoom lens according to any one of [1] to [4] above, wherein the aperture diaphragm moves independently of the second lens group and the lens group located closest to the object side in the subsequent lens group, and the aperture diameter changes, when zooming from the wide-angle end to the telephoto end.
[6]
The zoom lens according to any one of [1] to [5] above, further comprising a sub-diaphragm arranged closer to an image plane than the aperture diaphragm, the diameter of which changes when zooming from a wide-angle end to a telephoto end.
[7]
The zoom lens according to any one of the above [1] to [6], which satisfies the following conditional expression:
0.9<|R2f-R2r|/|R2f+R2r|<10.0...(3)
however,
R2f: radius of curvature of the surface of the second lens group closest to the object side, and R2r: radius of curvature of the surface of the second lens group closest to the image surface side.
[8]
a zoom lens and an image sensor that outputs an image signal corresponding to an optical image formed by the zoom lens;
The zoom lens comprises:
From the object side to the image plane side,
a first lens group having a negative meniscus lens with a convex surface facing the object side and having negative refractive power,
a second lens group having negative refractive power and moving toward the image surface side during focusing;
The aperture stop as the main aperture,
and a subsequent group including at least one lens group having a positive refractive power;
An image pickup apparatus in which the spacing between adjacent lens groups changes when zooming from the wide-angle end to the telephoto end, and the following condition is satisfied:
0.2<f1/f2<0.9...(1)
however,
f1: focal length of the first lens group, and f2: focal length of the second lens group.
[9]
The zoom lens according to any one of the above [1] to [7], further comprising a lens having substantially no refractive power.
[10]
The imaging device according to the above-mentioned [8], wherein the zoom lens further comprises a lens having substantially no refractive power.

This application claims priority based on Japanese Patent Application No. 2020-64020, filed on March 31, 2020, in the Japan Patent Office, the entire contents of which are incorporated herein by reference.

Those skilled in the art will appreciate that various modifications, combinations, subcombinations, and variations may occur to those skilled in the art depending on design requirements and other factors, and that these are intended to be within the scope of the appended claims and their equivalents.

Claims (7)

From the object side to the image plane side,
a first lens group having a negative meniscus lens with a convex surface facing the object side and having negative refractive power,
a second lens group having negative refractive power and moving toward the image surface side during focusing;
The aperture stop as the main aperture,
a third lens group having a positive refractive power;
a fourth lens group having a positive refractive power;
the first lens group includes a positive lens disposed closer to an image surface than the negative meniscus lens,
A zoom lens, wherein, during zooming from a wide-angle end to a telephoto end, the first lens group and the second lens group move toward the image plane side, and the third lens group and the fourth lens group move toward the object side, such that a distance between adjacent lens groups changes, and the following conditional expression is satisfied:
0.2<f1/f2<0.9...(1)
however,
f1: focal length of the first lens group, and f2: focal length of the second lens group. The zoom lens according to claim 1 , wherein the second lens group is composed of a single lens component. The zoom lens according to claim 1 , which satisfies the following condition:
0.7<Bfw/fw<1.4...(2)
however,
Bfw: back focus at the wide-angle end fw: focal length of the entire system at the wide-angle end. The zoom lens according to claim 1 , wherein the aperture diaphragm moves independently of the second lens group and the third lens group and changes its aperture diameter during zooming from a wide-angle end to a telephoto end. The zoom lens according to claim 1 , further comprising a sub-diaphragm that is disposed closer to an image plane than the aperture diaphragm and whose diameter changes when zooming from a wide-angle end to a telephoto end. The zoom lens according to claim 1 , which satisfies the following condition:
0.9<|R2f-R2r|/|R2f+R2r|<10.0...(3)
however,
R2f: radius of curvature of the surface of the second lens group closest to the object side, and R2r: radius of curvature of the surface of the second lens group closest to the image surface side. a zoom lens and an image sensor that outputs an image signal corresponding to an optical image formed by the zoom lens;
The zoom lens comprises:
From the object side to the image plane side,
a first lens group having a negative meniscus lens with a convex surface facing the object side and having negative refractive power,
a second lens group having negative refractive power and moving toward the image surface side during focusing;
The aperture stop as the main aperture,
a third lens group having a positive refractive power;
a fourth lens group having a positive refractive power;
the first lens group includes a positive lens disposed closer to an image surface than the negative meniscus lens,
an imaging device in which, during zooming from a wide-angle end to a telephoto end, the first lens group and the second lens group move toward the image plane side, and the third lens group and the fourth lens group move toward the object side, such that a distance between adjacent lens groups changes, and the following conditional expression is satisfied:
0.2<f1/f2<0.9...(1)
however,
f1: focal length of the first lens group, and f2: focal length of the second lens group.

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