JP7404064B2 - Imaging device - Google Patents

Description

The present invention relates to an imaging device having a plurality of optical systems.

For omnidirectional imaging and panoramic imaging, it has multiple optical systems and an imaging element provided for each optical system, and stitching processing is used to connect multiple captured images obtained by these multiple imaging optical systems to each other. An imaging device that performs this is used. Patent Document 1 discloses an imaging device that uses a mirror surface to bring the nodal points (entrance pupils) of a plurality of optical systems close to each other, thereby reducing misalignment of joints caused by stitch processing.

Japanese Patent Application Publication No. 2004-184862

In the above-mentioned imaging devices, when increasing the number of optical systems and image sensors or increasing the size of each image sensor in order to achieve higher image quality and wider angle of view, adjacent optical systems and image sensors may interfere with each other. In order to avoid this, there is a risk that the imaging device may become larger or its power consumption may increase.

The present invention provides an imaging device that can reduce the number of imaging elements used in a plurality of optical systems for obtaining a plurality of captured images that are linked together.

An imaging device according to an aspect of the present invention is an imaging device having a plurality of optical systems, wherein the extension lines of the optical axes of lenses closest to the object of each of the plurality of optical systems intersect with each other. It has a plurality of image sensors arranged to photoelectrically convert optical images formed by a plurality of optical systems. Each of the plurality of optical systems includes a negative lens group, a positive lens group disposed on the image side of the negative lens group with a maximum air gap in the optical system from the negative lens group, and a positive lens group in the area of the maximum air gap. It is configured by arranging a plurality of reflective surfaces . The plurality of optical systems includes two optical systems adjacent to each other . The plurality of image sensors is characterized in that one image sensor is provided for each of the two optical systems.

According to the present invention, it is possible to reduce the number of image sensors used for a plurality of optical systems for obtaining a plurality of captured images that are linked together. Further, it is possible to perform a process of joining a plurality of captured images by simple image processing.

1 is a diagram showing an optical configuration of an imaging device according to Example 1 (numerical example 1) of the present invention. FIG. FIG. 3 is a diagram showing an image circle on an image sensor in Example 1. FIG. FIG. 3 is a diagram showing an optical configuration of an imaging device according to a second embodiment (numerical example 2) of the present invention. 7 is a diagram showing an image circle on an image sensor in numerical example 2. FIG. FIG. 3 is a cross-sectional view showing the infinity focusing state of the optical system of Numerical Example 1. FIG. 4 is an aberration diagram showing the infinity focusing state of the optical system of Numerical Example 1. FIG. 7 is a cross-sectional view showing the infinity focusing state of the optical system of Numerical Example 2. FIG. 7 is an aberration diagram showing the infinity focusing state of the optical system of Numerical Example 2. FIG. 7 is a cross-sectional view showing the infinity focusing state of the optical system of Numerical Example 3. FIG. 7 is an aberration diagram showing the infinity focusing state of the optical system of Numerical Example 3. A cross-sectional view of the optical system. FIG. 3 is a diagram showing the arrangement of a plurality of optical systems. FIG. 3 is a diagram showing two optical systems adjacent to each other. FIG. 3 is a diagram showing reflective surfaces in two optical systems that are adjacent to each other. The figure which shows the image circle of two mutually adjacent optical systems.

Embodiments of the present invention will be described below with reference to the drawings. The imaging device of each embodiment described below includes a plurality of optical systems arranged in mutually different directions in the circumferential direction, and one imaging element provided for each two adjacent optical systems among the plurality of optical systems. and connects a plurality of captured images captured through a plurality of optical systems. As a result, wide-angle images such as omnidirectional images and panoramic images are obtained.

An image matching method such as pattern matching is used to join the captured images, but if the nodal points of a plurality of optical systems are different from each other, parallax occurs and a shift occurs at the joint of the captured images. Furthermore, when increasing the number of optical systems or increasing the size of the image sensor to achieve higher image quality, it is necessary to increase the distance between the optical systems to avoid interference between the nodal points. The distance becomes large, making it difficult to connect the captured images.

However, as shown in FIG. 11, by including the reflective surface RP1 in the optical system 50 and bending the optical axis (optical path) of the optical system 50 at right angles to the horizontal direction, nodal points can be achieved even when many optical systems are used. It becomes possible to shorten the distance between them. In the following description, the direction in which the optical axis on the incident side of the optical system (fisheye lens) extends is defined as the X direction, and the direction in which the optical axis extending in the X direction is bent by the reflective surface RP1 is defined as the Y direction, which is perpendicular to the X and Y directions. The direction perpendicular to the plane of the drawing is defined as the Z direction.

FIG. 12 shows an imaging device in which six (N) optical systems 50 shown in FIG. 11 are arranged on the same plane (XZ plane) in different directions in the circumferential direction, as seen from the Y direction (above). . In FIG. 12, the optical system facing the lower left is taken as a reference lens, and the direction in which the optical axis of this reference lens extends is taken as the X direction.

When six optical systems are arranged in different directions in the circumferential direction on the same plane, in order to perform imaging with the entire 360° angle of view divided by the six optical systems, the light of the six optical systems must be It is preferable that the angle between the axes is 60° (=360°/N). In this case, the six optical systems can be the same optical system. In addition, if the six optical systems are arranged in different directions in the Y direction, parallax will occur between the captured images acquired through them, and misalignment will occur at the joint of the captured images. It is preferable that the optical axis of the side (lens group closest to the object) and its extension line are on the same plane, and that the extension lines intersect on the same plane, and more preferably, that they intersect at one point.

If the six optical systems arranged as shown in FIG. 12 are configured without using a reflective surface, it will be necessary to separate the six optical systems from each other to avoid interference with the image sensor, and as a result, as described above, the captured image It becomes difficult to connect the images, and the overall size of the imaging device increases. By using a reflective surface, the nodal points can be brought closer to each other, and the imaging device can be downsized. However, as the number of optical systems increases, the number of image sensors also increases, leading to problems such as power consumption and heat generation. Furthermore, if the size of the image pickup device is increased in order to improve image quality, even if a reflective surface is used, the image pickup devices will interfere with each other after bending the optical axis, resulting in the need to increase the distance between the optical systems.

Therefore, in the imaging device of each embodiment, one imaging element is provided for two optical systems 60 adjacent to each other in the circumferential direction among the plurality of optical systems, as shown in FIG. A plurality of reflective surfaces are used in each of these two optical systems so that each of the optical systems 60 forms an image on the same image sensor.

With this configuration, the number of image pickup elements can be reduced relative to the number of optical systems, and the size of the image pickup apparatus can be reduced. Note that it is desirable to provide one image sensor for each of M (=N/2) sets of optical systems when two adjacent optical systems form a set. One image sensor may be provided for at least one set of optical systems.

In addition, in the following description, as shown in FIG. Let θ be the angle between the two incident optical axes of the system. At this time, if the reflective surface included in each optical system only bends the optical axis of the optical system 60 in the vertical direction, the image circles of the two optical systems on the image sensor will both be similar to that of the image, as shown in FIG. The circle is rotated so that the horizontal line and the vertical line perpendicular to the horizontal line are shifted by θ/2 with respect to the pixel arrangement direction in the long side direction (horizontal direction) and short side direction (vertical direction) of the image sensor. The horizontal line of the image circle is a straight line connecting the vertices of the lens surfaces closest to the object in each of the two optical systems. When joining the captured images, it is necessary to align the horizontal lines of the respective captured images, so it is necessary to correct the rotation of the image circle.

If the horizontal line of the captured image is not parallel (does not match) with the pixel arrangement direction of the image sensor, and the rotation of the image circle is corrected by image processing, the image quality will deteriorate because interpolation processing is required for the captured image, and the interpolation Computation time is also required for processing. In order to eliminate the need for interpolation processing, it is necessary to make the horizontal line of the image circle parallel to (coincide with) the pixel arrangement direction of the imaging device.

Therefore, in the imaging device of each embodiment, the rotation of the image circle that occurs depending on the angle θ of the two optical systems is corrected by a plurality of reflective surfaces provided in each of the two optical systems adjacent to each other. reflect the light (i.e. bend the optical axis).

FIG. 1 shows two adjacent optical systems 10 from above in the Y direction among six optical systems 10 arranged in different directions in the circumferential direction on the XZ plane in the imaging device of Example 1 (Numerical Example 1). Look and show. In Example 1, each optical system 10 has three reflective surfaces RP1, RP2, and RP3.

The reflective surface RP1 bends the optical axis of the optical system 10 at an angle of 90° in the Z direction toward an intermediate position between the two optical systems 10. The reflective surface RP2 bends the optical axis bent by the reflective surface RP1 at an angle of 90°-θ/2° within the XZ plane (in a direction parallel to the same plane). The reflective surface RP3 bends the optical axis bent by the reflective surface RP2 at an angle of 90° in the Y direction (a direction having a component perpendicular to the same plane) and guides it onto an image sensor (not shown). With this configuration, as shown in FIG. 2, the two optical systems 10 form two optical images on one image sensor.

The image sensor captures two optical images (photoelectrically converts them) and outputs an image signal to an image processing unit (image processing means) 101. The image processing unit 101 is provided within the imaging device, and performs various image processing on the imaging signal to generate two captured images corresponding to the two optical images. Furthermore, the image processing unit 101 generates four captured images using the imaging signals from the two image sensors that captured the optical images formed by the other four optical systems, and performs processing to connect all six captured images. to generate an omnidirectional image.

Note that, as shown in parentheses in FIG. 2, a personal computer 102 capable of executing processing equivalent to the image processing unit 101 is used as an image processing device separately from the imaging device, and an imaging system is configured by the imaging device and the image processing device. You may.

By bending the optical axis at an angle of 90°-θ/2° with the reflective surface RP2, the rotation of the image circle caused by the angle θ between the incident optical axes of the two optical systems 10 is corrected, and the image circle is The horizontal line is aligned with the pixel arrangement direction (long side direction) of the image sensor. By correcting the horizontal line of the image circle in this way, there is no need to rotate the captured images when stitching them together, so it is possible to stitch captured images without deterioration due to rotation processing, and the calculation time for rotation processing can also be reduced. No longer needed.

In this example, when correcting the rotation of the image circle using the reflection angle of the reflective surface, it is not necessary to correct it to exactly 90°-θ/2°, but as long as it is within the range of 90°-θ/2°±5°. Even if some rotation of the image circle occurs, misalignment at the joints of captured images can be suppressed to a level that does not pose a problem. Further, even if the rotation of the image circle that occurs in this range is corrected by image processing, the deterioration due to interpolation processing is slight.

Note that it is more preferable to set the reflection angle of the reflective surface to 90°-θ/2°±3°, since this makes misalignment at the joint between the captured images less noticeable.

Further, in this embodiment, the rotation of the image circle is corrected using only the reflective surface RP2, but it may be corrected using the two reflective surfaces RP1 and RP2. In this case, two optical images formed by two optical systems can be formed on one image sensor without bending the optical axis in the Y direction by the reflective surface RP3, but the lens thickness on the XZ plane becomes larger. As a result, in order to avoid interference between the image sensor provided for the two illustrated optical systems and the image sensor provided for the unillustrated optical system adjacent to these two optical systems, the optical systems are separated from each other. It becomes necessary to arrange them apart, which increases the size of the imaging device.

FIG. 3 shows two adjacent optical systems 20 from above in the Y direction among six optical systems 20 arranged in mutually different directions in the circumferential direction on the XZ plane in the imaging device of Example 2 (Numerical Example 2). Look and show.

In Example 2, each optical system 20 has two reflective surfaces RP1 and RP2. The reflective surface RP1 bends the optical axis of the optical system 20 toward an intermediate position between the two optical systems 20 at an angle of 90°+θ/2° within the XY plane (in a direction parallel to the same plane). The reflective surface RP2 bends the optical axis reflected by the reflective surface RP1 at an angle of 90 degrees in the Y direction (a direction having a component orthogonal to the same plane) and guides it to an image sensor (not shown).

With this configuration, as shown in FIG. 4, the two optical systems 20 form two optical images on one image sensor. By bending the optical axis at an angle of 90° + θ/2° by the reflective surface RP1, the rotation of the image circle caused by the angle θ between the incident optical axes of the two optical systems 20 is corrected, and the horizontal line of the image circle is Match the pixel arrangement direction (short side direction) of the image sensor. Therefore, in this embodiment, rotation processing of the captured images is required when joining the captured images, but since interpolation processing is not required in the rotation processing, captured images can be joined without deterioration due to rotation processing. .

In this example, when correcting the rotation of the image circle using the reflection angle of the reflective surface, it is not necessary to correct it to exactly 90° + θ/2°, but as long as the image circle is within the range of 90° + θ/2° ± 5°. Even if some rotation occurs, the misalignment at the joint between the captured images can be suppressed to a level that does not pose a problem. Further, even if the rotation of the image circle that occurs in this range is corrected by image processing, the deterioration due to interpolation processing is slight.

Note that it is more preferable to set the reflection angle of the reflective surface to 90°+θ/2°±3° because misalignment at the joint between the captured images becomes less noticeable.

As explained above, in an imaging device that connects captured images acquired through multiple optical systems and multiple imaging devices to obtain a wide-angle image, it is possible to realize a compact imaging device that reduces the number of imaging devices. be able to. Further, it is possible to perform a process of joining a plurality of captured images by simple image processing.

5, FIG. 7, and FIG. 9 show the configurations of the optical systems of Numerical Example 1, Numerical Example 2, and Numerical Example 3, respectively. In these figures, the left side is the object side, and the right side is the image side. L1 indicates the first lens group, and L2 indicates the second lens group. SP indicates an aperture stop, and IP indicates an image plane.

In an imaging device such as a video camera or a digital still camera, an imaging surface of an imaging element (photoelectric conversion element) such as a CCD sensor or a CMOS sensor is arranged on the image plane. FIG. 5, FIG. 7, and FIG. 8 each show the optical paths bent by the reflecting surfaces (RP1, RP2, RP3) developed. Numerical Example 1 and Numerical Example 2 use a mirror as a reflective surface, and Numerical Example 3 uses a prism as a reflective surface.

FIG. 6, FIG. 8, and FIG. 10 are aberration diagrams of Numerical Example 1, Numerical Example 2, and Numerical Example 3, respectively. Fno is the F number, and ω is the half angle of view. d is the d-line (wavelength 587.6 nm), and g is the g-line (wavelength 435.8 nm). In the astigmatism diagram, ΔM and ΔS indicate astigmatism at the meridional image plane and the sagittal image plane at the d-line, respectively. Distortion aberration shown is for the d-line. The optical system of each example is a conformal projection type optical system, and the distortion aberration diagram represents the deviation from the ideal image height in the conformal projection type. The chromatic aberration of magnification diagram shows the chromatic aberration of magnification for the g-line.

The specific configuration of each numerical example will be described below.
(Numerical example 1)
The optical system 10 of Numerical Example 1 shown in FIG. 5 includes a first lens group (negative lens group) L1 and a second lens arranged in order from the object side to the image side with a maximum air gap in between. group (positive lens group) L2, and three reflective surfaces RP1, RP2, and RP3 are arranged in the region of maximum air spacing. An aperture stop SP is arranged within the second lens group L2.

The optical system 10 in this numerical example has a total angle of view of 180.0°, an F number of 4.0, an image circle diameter of 17.5 mm, and two optical systems are arranged on a full-size image sensor. Form an optical image.

In this numerical example, in order to capture an image with an angle of view of 360° in the horizontal circumferential direction using six optical systems, one optical system only needs to have an angle of view of 60°. However, in order to improve the precision of pattern matching in the stitching process that connects captured images acquired through six optical systems, each optical system has a view angle wider than 60°.

In addition, the right half images of each of the six captured images acquired through the six optical systems are cut out and joined together to form an image for the right eye, and similarly each of the six captured images acquired through each optical system is It is also possible to present an image that can be viewed stereoscopically by cutting out the left half of the image and joining them together to create an image for the left eye. Therefore, the angle of view of the optical system in this numerical example is set to 180°.

In the optical system of each example (numerical example), the focal length of the first lens group L1 is fn, the focal length of the second lens group L2 is fp, the focal length of the entire optical system is f, and the maximum air When the interval is L, the following conditions of equations (1) and (2) are satisfied.
-0.25≦fn/L≦-0.05 (1)
1,80≦fp/f≦6.50 (2)
The condition of formula (1) is a condition regarding miniaturization of the imaging device. If fn/L exceeds the upper limit of equation (1), the negative refractive power of the first lens group L1 will be too large and off-axis aberrations such as field curvature and distortion will become large, which is not preferable. Increasing the number of lenses for aberration correction is not preferable because the distance between nodal points of adjacent optical systems increases, making it difficult to connect captured images. When fn/L is less than the lower limit of equation (1), the negative refractive power of the first lens group L1 is too small to converge off-axis rays near the optical axis, and the reflective surface becomes large. As a result, there is interference between the reflective surface and the first lens group L1 and interference between the reflective surfaces, which is not preferable.

It is more preferable to set the range of formula (1) as follows.
-0.23≦fn/L≦-0.10 (1a)
It is more preferable to set the range of formula (1) as follows.
-0.21≦fn/L≦-0.12 (1b)
The condition of equation (2) is a condition for two adjacent optical systems to form two optical images on one image sensor. If fp/f exceeds the upper limit of formula (2), the positive refractive power of the second lens group L2 will be too small and the second lens group L2 will become large, causing a problem of interference between the optical systems, so it is preferable. do not have. If fp/f is less than the lower limit value of equation (2), the positive refractive power of the second lens group L2 is too large, which increases spherical aberration and coma aberration and deteriorates optical performance, which is not preferable.
It is more preferable to set the range of formula (2) as follows.

2.00≦fp/f≦6.00 (2a)
It is more preferable to set the range of formula (2) as follows.
2.20≦fp/f≦5.50 (2b)
The configuration of each lens group in the optical system 10 of Numerical Example 1 will be explained. The first lens group L1 includes, in order from the object side to the image side, a negative meniscus lens with a convex shape on the object side and a negative meniscus lens with a convex shape on the object side. By arranging an aspherical surface on the image side of the negative meniscus lens closest to the object, field curvature can be corrected favorably.

The second lens group L2 includes, in order from the object side to the image side, a positive meniscus lens convex on the object side, an aperture stop SP, a cemented lens of a biconvex lens and a negative meniscus lens convex on the image side, a biconvex lens, and a biconvex lens. It has a cemented lens of a concave lens and a biconvex lens, a cemented lens of a biconvex lens and a biconcave lens, a cemented lens of a biconvex lens and a biconcave lens, and a biconvex lens. A cemented lens of a biconvex lens and a biconcave lens has an aspherical surface on its most image-side surface, so that astigmatism can be corrected well. In addition, it has a cemented lens of a biconvex lens and a biconcave lens, and a final lens as a biconvex lens, and by making the image side surface of the final lens aspheric, it is possible to satisfactorily correct field curvature and distortion. can.

Note that when the reflective surface is a surface of a prism as described above, the maximum air spacing mentioned above is the maximum air spacing between surfaces having refractive power excluding the prism.

According to this numerical example, it is possible to align the horizontal line of the image circle with the pixel arrangement direction (long side direction) of the image sensor by the three reflecting surfaces of each of the two optical systems adjacent to each other in the horizontal circumferential direction. can.
(Numerical example 2)
The optical system 20 of Numerical Example 2 shown in FIG. 7 includes a first lens group (negative lens group) L1 and a second lens arranged in order from the object side to the image side with the maximum air gap in between. group (positive lens group) L2, and two reflective surfaces RP1 and RP2 are arranged in the region of maximum air spacing. An aperture stop SP is arranged within the second lens group L2.

The optical system 20 in this numerical example has a total angle of view of 180.0°, an F number of 4.07, and an image circle diameter of 17.5 mm. Form an optical image. In this numerical example as well, an image of 360° angle of view in the horizontal circumferential direction is captured by six optical systems.

The configuration of each lens group in the optical system 20 of Numerical Example 2 will be explained. The first lens group L1 includes, in order from the object side to the image side, a negative meniscus lens having a convex shape on the object side and a biconcave lens. By arranging an aspherical surface on the image side of the negative meniscus lens closest to the object, field curvature can be corrected favorably.

The second lens group L2 includes, in order from the object side to the image side, a biconvex lens, an aperture stop SP, a positive meniscus lens with a convex surface on the object side, a cemented lens of a biconcave lens and a biconvex lens, a biconvex lens and a negative meniscus lens with a convex surface on the image side. It has a cemented lens with By providing an aspherical surface on the image side of a negative meniscus lens having a convex surface on the image side, spherical aberration can be favorably corrected. Furthermore, the second lens group L2 includes a cemented lens of a biconvex lens and a biconcave lens, and a biconvex lens. By making the image side surface of the biconvex lens as the final lens aspheric, field curvature and distortion can be corrected well.

According to this numerical example, the two reflective surfaces of the two optical systems adjacent to each other in the horizontal circumferential direction make it possible to align the horizontal line of the image circle with the pixel arrangement direction (short side direction) of the image sensor. can.

FIG. 9 shows an optical system 30 of Example 3 (Numerical Example 3). The optical system 30 of Numerical Example 3 includes a first lens group (negative lens group) L1 and a second lens group (positive lens group) arranged in order from the object side to the image side with a maximum air gap in between. group) L2, and two reflective surfaces RP1 and RP2 are arranged as prism surfaces in the region of maximum air spacing. An aperture stop SP is arranged within the second lens group L2.

The optical system 30 in this numerical example has a total angle of view of 150.0°, an F number of 4.0, an image circle diameter of 17.5 mm, and two optical systems are arranged on a full-size image sensor. Form an optical image.

In this numerical example, since eight optical systems capture an image with an angle of view of 360° in the horizontal circumferential direction, the angle of view of each optical system 30 is narrower than in numerical examples 1 and 2. Further, in this numerical example, the horizontal line of the image circle is made to coincide with the pixel arrangement direction (short side direction) of the image sensor by the two reflecting surfaces of the two optical systems that are adjacent to each other in the horizontal circumferential direction.

In this numerical example, the angle θ between the incident optical axes of two adjacent optical systems among the eight optical systems 30 is 45°. Therefore, the optical axis of each optical system 30 is bent at an angle of 112.5° by the reflective surface RP1 of the prism, and the optical axis bent by the reflective surface RP1 is bent at an angle of 90° in the Y direction to form one image sensor. lead to. Thereby, two optical systems adjacent to each other form two optical images on one image sensor.

The configuration of each lens group in the optical system 30 of Numerical Example 3 will be explained. The first lens group L1 includes, in order from the object side to the image side, a first negative meniscus lens having a convex shape on the object side and a second negative meniscus lens having a convex surface on the object side. By arranging the aspherical surface on the image side of the second negative meniscus lens, field curvature can be favorably corrected.

The second lens group L2 includes an aperture stop SP, a biconvex lens, a cemented lens of a biconcave lens and a biconvex lens, a cemented lens of a biconvex lens and a negative meniscus lens with a convex surface on the image side, a cemented lens of a biconvex lens and a biconcave lens, and a convex lens. has. By making the image side of the convex lens, which is the final lens, an aspherical surface, field curvature and distortion can be favorably corrected.

Note that when the reflective surface is constituted by the surface of a prism as in this numerical example, L in the above-mentioned formula (1) is the distance between the surfaces having refractive power before and after the prism.

In each of the above numerical examples, a case is explained in which six or eight optical systems are used as an imaging device that obtains a wide-field image of 360° in the horizontal circumferential direction, but the number of optical systems is not limited to these, and higher image quality The number of optical systems may be increased in order to improve the image quality, or the number of optical systems may be reduced if a wide field of view of 360° in the horizontal circumferential direction is not required.

Specific numerical data for numerical examples 1 to 3 are shown below. In each numerical example, i indicates the order counted from the object side, ri is the radius of curvature of the i-th optical surface (i-th surface), and di is the axial distance between the i-th surface and the (i+1)-th surface. (lens thickness or air spacing). ndi is the refractive index at the d-line of the material of the i-th optical member. νdi is the Abbe number of the material of the i-th optical member with respect to the d-line. BF represents back focus (mm). "Back focus" is the distance on the optical axis from the final surface of the optical system (the lens surface closest to the image side) to the paraxial image surface expressed in air equivalent length. The "total lens length" is the distance on the optical axis from the frontmost surface (lens surface closest to the object side) to the final surface of the zoom lens plus the back focus.

The Abbe number νd of a certain material is given by νd = (where the refractive index at the Fraunhofer line d line (587.6 nm), F line (486.1 nm), and C line (656.3 nm) is Nd, NF, and NC. It is expressed as Nd-1)/(NF-NC).

The "*" attached to the surface number means that the surface has an aspherical shape. In the aspherical shape, the optical axis direction is the X axis, the direction perpendicular to the optical axis is the H axis, and the direction of light travel is positive. When R is the paraxial radius of curvature, K is the conic constant, and A4 to A10 are the aspheric coefficients, it is expressed by the following formula.

The aspherical coefficient "ex" means 10 ^-x .

Further, Table 1 summarizes the conditions and relationships of Numerical Examples 1 to 3 and the aforementioned equations (1) and (2).
[Numerical example 1]
Unit: mm

Surface data Surface number rd nd νd Effective diameter
1 26.643 1.00 1.85400 40.4 29.12
2* 13.240 5.12 22.72
3 192.948 0.64 2.00069 25.5 17.03
4 7.875 7.94 12.53
5 (RP1) ∞ 11.98
6 (RP2) ∞ 9.00
7 (RP3) ∞ 4.99
8 15.073 1.25 2.00069 25.5 10.06
9 71.776 0.80 9.97
10(Aperture) ∞ 0.50 9.98
11 72.256 2.94 1.48749 70.2 9.99
12 -10.465 0.80 2.00100 29.1 9.93
13 -17.270 0.50 10.24
14 24.183 2.99 1.48749 70.2 10.01
15 -14.602 0.50 9.63
16 -15.404 0.80 1.95375 32.3 9.16
17 8.306 2.38 1.59270 35.3 9.04
18 -29.904 0.15 9.22
19 10.744 3.68 1.49700 81.5 9.59
20 -8.165 0.80 1.85400 40.4 9.39
21* 61.534 4.52 9.68
22 9.822 3.82 1.43875 94.7 10.65
23 -10.355 0.80 2.00100 29.1 10.42
24 28.513 5.60 10.79
25 37.843 2.84 1.58313 59.4 15.00
26* -15.388 4.47 15.30
Image plane ∞

Aspheric data 2nd surface
K = 5.66334e-002 A 4=-9.14085e-006 A 6=-1.72836e-007 A 8= 1.21712e-009 A10=-3.53560e-011

Page 21
K = 0.00000e+000 A 4=-1.83484e-004 A 6=-1.49778e-006 A 8=-5.63221e-008 A10= 9.70871e-010

Page 26
K = 0.00000e+000 A 4= 2.56291e-004 A 6= 1.58376e-006 A 8=-1.30861e-008

Various data focal length 5.57
F number 4.00
Half angle of view (°) 90.00
Image height 8.75
Lens total length 80.80
BF 4.47

Entrance pupil position 9.60
Exit pupil position -75.03
Front principal point position 14.78
Back principal point position -1.10

Lens group data group Starting surface Ending surface Focal length Lens length Front principal point position Rear principal point position
L1 1 4 -5.82 6.76 4.58 -0.88
L2 8 26 27.16 35.66 14.94 -48.65

Single lens data lens Starting surface Focal length
1 1 -31.92
2 3 -8.22
3 8 18.86
4 11 18.97
5 12 -28.19
6 14 19.16
7 16 -5.57
8 17 11.23
9 19 9.98
10 20 -8.40
11 22 12.19
12 23 -7.51
13 25 19.14

[Numerical example 2]
Unit: mm

Surface data Surface number rd nd νd Effective diameter
1 32.384 1.00 1.85400 40.4 31.00
2* 12.197 6.42 22.41
3 -395.651 0.80 1.88300 40.8 18.64
4 8.947 16.30 13.89
5(RP1) ∞ 12.20
6(RP2) ∞ 4.50
7 326.989 0.89 1.59522 67.7 9.81
8 -41.091 0.80 9.89
9(Aperture) ∞ 0.50 9.98
10 7.489 3.84 1.49700 81.5 10.18
11 83.915 3.65 9.15
12 -15.404 0.80 1.95375 32.3 6.81
13 6.516 1.67 1.80518 25.4 6.56
14 -35.537 0.15 6.54
15 9.768 4.00 1.49700 81.5 6.67
16 -5.033 0.80 1.85400 40.4 6.79
17* -23.149 5.74 7.45
18 10.322 3.34 1.43875 94.7 9.99
19 -10.452 0.80 2.00100 29.1 9.90
20 28.882 5.13 10.45
21 326.683 3.00 1.58313 59.4 14.80
22* -13.363 4.47 15.30
Image plane ∞

Aspheric data 2nd surface
K =-1.16416e+000 A 4= 7.37125e-005 A 6=-2.92217e-007 A 8= 6.55174e-009 A10=-4.66004e-011

Page 17
K = 0.00000e+000 A 4=-2.97087e-005 A 6=-5.08814e-006 A 8=-1.43019e-007 A10= 5.92727e-010

Page 22
K = 0.00000e+000 A 4= 7.55621e-005 A 6= 1.23089e-006 A 8=-4.82964e-009

Various data focal length 5.57
F number 4.07
Half angle of view (°) 90.00
Image height 8.75
Lens total length 80.80
BF 4.47

Entrance pupil position 9.72
Exit pupil position -60.64
Front principal point position 14.82
Back principal point position -1.10

Lens group data group Starting surface Ending surface Distance Lens configuration length Front principal point position Rear principal point position
L1 1 4 -5.82 8.22 4.71 -1.62
L2 7 22 25.19 35.11 11.09 -44.81

Single lens data lens Starting surface Focal length
1 1 -23.44
2 3 -9.90
3 7 61.38
4 10 16.27
5 12 -4.72
6 13 6.96
7 15 7.34
8 16 -7.69
9 18 12.45
10 19 -7.59
11 21 22.09

[Numerical example 3]
Unit: mm
Surface data Surface number rd nd νd Effective diameter
1 32.384 1.00 1.85400 40.4 24.14
2* 13.561 3.92 19.63
3 161.648 0.80 1.88300 40.8 16.54
4 8.087 3.89 12.39
5 ∞ 12.00 1.51633 64.1 11.98
6(RP1) ∞ 12.00 1.51633 64.1
7(RP2) ∞ 5.00 1.51633 64.1
8 ∞ 0.50 7.91
9(Aperture) ∞ 0.50 8.05
10 8.746 3.19 1.49700 81.5 8.46
11 -88.652 3.96 8.07
12 -15.404 0.80 1.95375 32.3 6.82
13 7.105 1.82 1.80518 25.4 6.93
14 -24.210 0.15 7.03
15 10.033 2.73 1.49700 81.5 7.62
16 -8.482 0.80 1.85400 40.4 7.78
17* -19.842 9.26 8.20
18 9.971 4.00 1.43875 94.7 11.17
19 -11.085 0.80 2.00100 29.1 10.97
20 22.907 4.05 11.44
21 -12686.417 2.69 1.58313 59.4 14.68
22* -18.607 5.52 15.23
Image plane ∞

Aspheric data 2nd surface
K =-1.36080e+000 A 4= 3.93355e-005 A 6=-2.17148e-007 A 8=-2.67024e-009 A10= 6.66356e-012

Page 17
K = 0.00000e+000 A 4= 9.46123e-005 A 6=-5.76222e-007 A 8=-1.33637e-008 A10=-1.91385e-010

Page 22
K = 0.00000e+000 A 4=-3.64361e-005 A 6= 7.49178e-007 A 8=-1.14787e-008

Various data focal length 6.69
F number 4.00
Half angle of view (°) 75.00
Image height 8.75
Lens total length 79.37
BF5.52

Entrance pupil position 8.75
Exit pupil position -34.36
Front principal point position 14.32
Back principal point position -1.17

Lens group data group Starting surface Ending surface Focal length Lens length Front principal point position Rear principal point position
L1 1 4 -6.50 5.72 3.62 -0.90
L2 9 22 17.47 34.74 3.54 -29.92

Single lens data lens Starting surface Focal length
1 1 -28.01
2 3 -9.66
3 5 0.00
4 6 0.00
5 7 0.00
6 10 16.19
7 12 -5.01
8 13 7.00
9 15 9.72
10 16 -17.93
11 18 12.70
12 19 -7.38
13 21 31.95

The embodiments described above are merely representative examples, and various modifications and changes can be made to each embodiment when implementing the present invention.

L1 1st lens group L2 2nd lens group RR1~RR3 Reflective surface

Claims (13)

An imaging device having a plurality of optical systems,
The plurality of optical systems are arranged such that extension lines of optical axes of lenses closest to the object of each of the plurality of optical systems intersect with each other,
comprising a plurality of image sensors that photoelectrically convert optical images formed by the plurality of optical systems,
Each of the plurality of optical systems includes a negative lens group, a positive lens group disposed on the image side from the negative lens group with a maximum air gap in the optical system from the negative lens group, and a positive lens group that has the maximum air gap. It is composed of multiple reflective surfaces arranged in the area of
The plurality of optical systems include two optical systems adjacent to each other ,
The image pickup device is characterized in that the plurality of image pickup devices include one image pickup device provided for each of the two optical systems. The plurality of optical systems are composed of M sets of optical systems when the two optical systems are one set,
The imaging device according to claim 1, wherein the plurality of imaging devices include M imaging devices. the number of the plurality of optical systems is N,
3. The imaging device according to claim 1, wherein the plurality of optical systems are arranged such that the angle between the extension lines of the plurality of optical systems is 360°/N. The optical axes of the lenses closest to the object in each of the plurality of optical systems are on the same plane,
The plurality of reflective surfaces are provided so that a straight line connecting the vertices of the lens surfaces closest to the object in the two optical systems is parallel to a pixel arrangement direction in the image sensor. 4. The imaging device according to any one of 1 to 3. The number of the plurality of reflective surfaces is two,
The angle formed by the extension lines of the two optical systems each having the two reflective surfaces is θ,
5. The imaging device according to claim 4, wherein the two reflective surfaces bend the optical axis of the optical system in a direction parallel to the same plane within a range of 90°+θ/2°±5°. An imaging device having a plurality of optical systems,
The plurality of optical systems are arranged such that extension lines of optical axes of lenses closest to the object of each of the plurality of optical systems intersect with each other,
comprising a plurality of image sensors that photoelectrically convert optical images formed by the plurality of optical systems,
The optical axes of the lenses closest to the object in each of the plurality of optical systems are on the same plane,
The plurality of optical systems include two optical systems adjacent to each other,
The number of reflective surfaces arranged in each of the two optical systems is two,
The two reflective surfaces are provided such that a straight line connecting the vertices of the lens surfaces closest to the object in the two optical systems is parallel to a pixel arrangement direction in the image sensor,
The angle formed by the extension lines of the two optical systems is θ,
The two reflective surfaces bend the optical axis of the optical system in a direction parallel to the same plane within a range of 90° + θ/2° ± 5°,
The image pickup device is characterized in that the plurality of image pickup devices include one image pickup device provided for each of the two optical systems. The number of the plurality of reflective surfaces is three,
The angle formed by the extension lines of the two optical systems each having the three reflecting surfaces is θ,
The imaging device according to claim 4, wherein the three reflecting surfaces bend the optical axis of the optical system in a direction parallel to the same plane within a range of 90°-θ/2°±5°. An imaging device having a plurality of optical systems,
The plurality of optical systems are arranged such that extension lines of optical axes of lenses closest to the object of each of the plurality of optical systems intersect with each other,
comprising a plurality of image sensors that photoelectrically convert optical images formed by the plurality of optical systems,
The optical axes of the lenses closest to the object in each of the plurality of optical systems are on the same plane,
The plurality of optical systems include two optical systems adjacent to each other,
The number of reflective surfaces arranged in each of the two optical systems is three,
The three reflective surfaces are provided so that a straight line connecting the vertices of the lens surfaces closest to the object in the two optical systems is parallel to a pixel arrangement direction in the image sensor,
The number of the plurality of reflective surfaces is three,
The angle formed by the extension lines of the two optical systems is θ,
The three reflective surfaces bend the optical axis of the optical system in a direction parallel to the same plane within a range of 90°-θ/2°±5°,
The image pickup device is characterized in that the plurality of image pickup devices include one image pickup device provided for each of the two optical systems. 9. One of the reflective surfaces bends the optical axis of the optical system in a direction having a component perpendicular to the same plane. The imaging device described in . When the focal length of the negative lens group is fn and the maximum air gap is L,
-0.25≦fn/L≦-0.05
8. The imaging device according to claim 1, wherein the imaging device satisfies the following conditions. When the focal length of the positive lens group is fp, and the focal length of the optical system is f,
1.80≦fp/f≦6.50
The imaging device according to any one of claims 1 to 5, 7, and 10, wherein the imaging device satisfies the following conditions. 12. The image processing apparatus according to claim 1 , further comprising an image processing means that performs a process of joining a plurality of captured images generated by imaging by the image sensor through the plurality of optical systems. imaging device. An imaging device according to any one of claims 1 to 12 ,
An imaging system comprising: an image processing device that performs a process of joining together a plurality of captured images generated by imaging by the image sensor through the plurality of optical systems.