Lens device and imaging device

Abstract

To provide a lens device that enables 360-degree field-of-view shooting while suppressing reflections of objects other than the subject. [Solution] The lens device has first and second optical systems and a mount, the first and second optical systems each having a first optical axis, a bent optical section, and a second optical axis extending from the object side to the image side, the mount has a central axis parallel to the second optical axes of the first and second optical systems and passing through the center of the mount, the first optical system has a first nodal point which is a node between the light taken in from the first optical system and the interior of the imaging device body, the second optical system has a second nodal point which is a node between the light taken in from the second optical system and the interior of the imaging device body, the central axis intersects with a straight line including the first optical axis of the first and second optical systems, and when projected onto a plane parallel to at least one of the first optical axes of the first and second optical systems and the central axis, the mount is positioned within a triangular region connecting one of the two points where the maximum angle of view portions of the incident light beams of the first and second optical systems intersect, and the first and second nodal points.

Description

Technical Field

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[0001] The present invention relates to a lens device capable of shooting with a 360-degree viewing angle.

Background Art

[0002] Patent Document 1 discloses a configuration for generating an image with a 360-degree viewing angle using two images obtained by two image sensors that receive light passing through each of two optical systems.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the configuration of Patent Document 1, even when the shooting conditions such as exposure are the same, color differences occur in the two images shot at the same time due to individual variations in the image sensors. Therefore, when generating an image with a 360-degree viewing angle, it is necessary to adjust the color while synchronizing the shooting times of the two images, and the post-shooting processing becomes complicated.

[0005] <0(000028>To avoid this, a configuration in which an interchangeable-lens imaging device having a single image sensor is equipped with an interchangeable lens capable of 360-degree shooting can be considered. However, an interchangeable lens capable of 360-degree shooting is close to the imaging device, and there is a concern that the imaging device side other than the subject may be reflected when performing 360-degree shooting.

[0006] An object of the present invention is to provide a lens device and an imaging device capable of shooting with a 360-degree viewing angle while suppressing reflection other than the subject.

Means for Solving the Problems

[0007] A lens device as one aspect of the present invention comprises a first optical system, a second optical system arranged in a different orientation from the first optical system, and a mount that can be attached to the main body of an imaging device, wherein the first optical system and the second optical system each have a first optical axis, a bent optical section, and a second optical axis, respectively, from the object side to the image side, and the mount has a central axis that is parallel to the second optical axis of the first optical system and the second optical system and passes through the center of the mount, and the first optical system has a node that is between the light taken in from the first optical system and the inside of the main body of the imaging device The first optical system has a nodal point, and the second optical system has a second nodal point which is a node between the light taken in from the second optical system and the interior of the imaging device body. When viewed projected onto a plane parallel to the first optical axis and the central axis of at least one of the first optical system and the second optical system, the mount is positioned within a triangular region connecting one of the two points where the maximum field of view portion of the incident light beam of the first optical system and the maximum field of view portion of the incident light beam of the second optical system intersect, the first nodal point, and the second nodal point. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a lens device and an imaging device that can capture images with a 360-degree field of view while suppressing reflections of objects other than the subject. [Brief explanation of the drawing]

[0009] [Figure 1] (a) an oblique view and (b) a side view of the lens device of the first embodiment. [Figure 2] This is an exploded perspective view of the lens device of the first embodiment. [Figure 3] This is a cross-sectional view of the lens device according to the first embodiment. [Figure 4] This diagram illustrates the non-photographic region of the lens device according to the first embodiment. [Figure 5] (a) an oblique view and (b) a side view of the lens device of the second embodiment. [Figure 6] This is a perspective view of the main components of the lens device according to the second embodiment. [Figure 7] This is a side view of the lens device according to the second embodiment. [Figure 8] This is a cross-sectional view of the lens device according to the second embodiment. [Figure 9] (a) an oblique view, (b) a side view, and (c) a side view of the imaging device according to the third embodiment. [Figure 10] This figure illustrates the area of ​​the imaging device in the third embodiment that cannot be photographed. [Figure 11] This figure shows the imaging surface of the image sensor of the imaging device according to the third embodiment. [Modes for carrying out the invention]

[0010] The embodiments of the present invention will be described in detail below with reference to the drawings. In each figure, the same reference numeral is used for identical components, and redundant explanations are omitted. [First Embodiment] Figures 1(a) and 1(b) are a perspective view and a side view of the lens device 1 of this embodiment, respectively. Figure 2 is an exploded perspective view of the lens device 1. Figure 3 is a cross-sectional view taken along line AA of Figure 1(b). Figure 4 is a diagram illustrating the non-photographic area of ​​the lens device 1, and is a wider area shown by reducing the scale of Figure 3.

[0011] The lens device 1 is an interchangeable lens capable of capturing images with a 360-degree field of view. The lens device 1 has a first optical system 100 and a second optical system 200 arranged in a different orientation from the first optical system 100, and is configured so that two image circles are formed side by side on the imaging surface of a single image sensor in the camera body, which is the imaging device body. In this embodiment, the two optical systems are arranged side by side in orientations 180 degrees apart. The lens device 1 also has an annular lens mount 300 that can be attached to the camera body. The lens mount 300 has a lens mount central axis O_3 that passes through the center of the annular shape. ΦD is the diameter (aperture, mount diameter) of the lens mount 300 and corresponds to the fitting diameter with the camera mount of the camera body. The lens mount 300 is fastened to the housing 520 with screws. The housing 520 has a lens holding member (not shown) inside that holds the two optical systems. Furthermore, the lens device 1 has a dustproof member 400 on the camera body mounting side of the lens mount 300 to prevent dust from entering the interior.

[0012] In each figure, the XYZ coordinate system is defined as follows: the X-axis is the direction parallel to the first optical axis O_11 of the first optical system 100; the Y-axis is the direction parallel to the lens mount central axis O_3; and the Z-axis is the direction perpendicular to the X and Y axes.

[0013] As shown in Figures 2 and 3, the configurations of the two optical systems are identical. The first optical system 100 has the lens group 111 closest to the object and is oriented in the negative direction of the X-axis. The second optical system 200 has the lens group 211 closest to the object and is oriented in the positive direction of the X-axis. Each of the two optical systems is either a wide-angle fisheye lens or a full-circumference fisheye lens, and has a field of view of 180 degrees or more. In the first optical system 100 (and the second optical system 200), the ring member 610 (620) masks the outer circumference of the lens surface closest to the object of the lens group 111 (211), thereby precisely controlling the field of view around the optical axis.

[0014] The configuration and arrangement of the two optical systems will be described below with reference to Figures 3 and 4. First, the configuration of the two optical systems will be described.

[0015] The first optical system 100 has a first optical axis O_11, a prism 120 (bending optical unit), and a second optical axis O_12, from the object side toward the image side. The light incident on the first optical system 100 travels along the first optical axis O_11, enters the prism 120, is bent by a reflecting surface 121 provided on the prism 120, passes through lens groups 131 and 132 along the second optical axis O_12, and enters an image pickup device within the camera body. In the present embodiment, the second optical axis O_12 is substantially orthogonal to the first optical axis O_11.

[0016] The second optical system 200 has a first optical axis O_21, a prism 220 (bending optical unit), and a second optical axis O_22, from the object side toward the image side. The light incident on the second optical system 200 travels along the first optical axis O_21, enters the prism 220, is bent by a reflecting surface 221 provided on the prism 220, passes through lens groups 231 and 232 along the second optical axis O_22, and enters an image pickup device within the camera body. In the present embodiment, the second optical axis O_22 is substantially orthogonal to the first optical axis O_21.

[0017] In the XY plane formed by the X-axis direction parallel to the first optical axis O_11 of the first optical system 100 and the Y-axis direction parallel to the lens mount central axis O_3, the extension line of the first optical axis O_11 and the lens mount central axis O_3 intersect at point E. Also, in the XY plane, the extension line of the first optical axis O_21 and the lens mount central axis O_3 intersect at point E. With such a configuration, internal calculations when generating an image with a 360-degree viewing angle are facilitated. In the present embodiment, the first optical system 100 and the second optical system 200 are arranged side by side in the X-axis direction, and as shown in FIG. 2, the first optical axis O_11 and the second optical axis O_12 are arranged on the same straight line. With such a configuration, when one of the central portions of the two image circles formed on the imaging surface of the image pickup device is a front image, the other becomes a rear image on the 180-degree opposite side, and internal calculations when generating an image with a 360-degree viewing angle become even easier.

[0018] Furthermore, in order for the first optical system 100 and the second optical system 200 to fit inside the lens mount 300, the distance L (distance between the second optical axes) between the second optical axes O_12 and O_22 is shorter than the mount diameter ΦD of the lens mount 300.

[0019] Next, we will explain the areas where imaging is impossible for the first optical system 100 and the second optical system 200. The field of view of the first optical system 100 is θ1, and the field of view of the second optical system 200 is θ2, and the field of view angles θ1 and θ2 are equal. Light taken in from the first optical system 100 intersects at point A1 (node, focal point, first nodal point) before reaching the inside of the camera body. Light taken in from the second optical system 200 intersects at point A2 (node, focal point, second nodal point) before reaching the inside of the camera body. Note that for wide-angle lenses with a field of view of 180 degrees or more, the nodal point is located closer to the object as the field of view is wider.

[0020] In the XY plane of Figure 4, the maximum field of view of the incident light beam incident on the first optical system 100 with a field of view angle θ1 is shown as a straight line B11 extending from point A1 toward the lens mount 300, and a straight line B12 extending toward the opposite side of the lens mount 300. The maximum field of view of the incident light beam incident on the second optical system 200 with a field of view angle θ2 is shown as a straight line B21 extending from point A2 toward the lens mount 300, and a straight line B22 extending toward the opposite side of the lens mount 300. Point C1 is the intersection of lines B11 and B21, and point C2 is the intersection of lines B12 and B22. Point C1 is the intersection on the lens mount 300 side, and point C2 is the intersection on the opposite side of the lens mount 300. The extension of the first optical axis O_11 and the line connecting points C1 and C2 intersect perpendicularly at point E. The distance F1 from the first optical axis O_11 to point C1 is equal to the distance F2 from the first optical axis O_11 to point C2. Also, the distance F3 from point E to point A1 is equal to the distance F4 from point E to point A2.

[0021] In this configuration, the area of ​​the lens device 1 that cannot be photographed in the XYZ space is a solid of revolution (biconical) space with the first optical axis O_11, which is the base of the isosceles triangle, as the axis of rotation in an isosceles triangle formed by points A1, A2, C1 or C2. In other words, the area of ​​the area of ​​unphotographable region in the XY plane is a quadrilateral (rhombus) region formed by points A1, C1, A2, and C2.

[0022] The lens mount 300 is located within a triangular region in the XY plane, which is included in the area where imaging is impossible. In other words, the lens device 1 can capture images with a 360-degree field of view while suppressing reflections from the lens mount 300. [Second Embodiment] In this embodiment, the arrangement of two main optical systems differs from that of the first embodiment. In this embodiment, only the configurations that differ from the first embodiment will be described, and the common configurations will not be described.

[0023] Figure 5 shows (a) a perspective view and (b) a side view of the lens device 2 in the second embodiment. Figure 6 is a perspective view of the main components of the lens device 2. Figure 7 is a side view of the lens device 2. Figure 8 is a cross-sectional view taken along line BB in Figure 5(b).

[0024] In each figure, the XYZ coordinate system is defined as follows: the X-axis is the direction parallel to the first optical axis O_71 of the first optical system 700; the Y-axis is the direction parallel to the lens mount central axis O_3; and the Z-axis is the direction perpendicular to the X and Y axes.

[0025] The lens device 2 has a first optical system 700 and a second optical system 800. The configurations of the first optical system 700 and the second optical system 800 are identical. The first optical system 700 has a first optical axis O_71, a prism 720 (bent optical section), and a second optical axis O_72, extending from the object side towards the image side. In this embodiment, the second optical axis O_72 is approximately perpendicular to the first optical axis O_71. The prism 720 has a reflective surface 721 that bends light traveling along the first optical axis O_71 in a direction parallel to the second optical axis O_72. The second optical system 800 has a first optical axis O_81, a prism 820 (bent optical section), and a second optical axis O_82, extending from the object side towards the image side. In this embodiment, the second optical axis O_82 is approximately perpendicular to the first optical axis O_81. The prism 820 is equipped with a reflective surface 821 that bends light traveling along the first optical axis O_81 in a direction parallel to the second optical axis O_82. Furthermore, the distance G (distance between the second optical axes) between the second optical axes O_72 and O_82 is smaller than the mount diameter ΦD of the lens mount 300 so that the first optical system 700 and the second optical system 800 can be housed inside the lens mount 300.

[0026] As shown in Figure 8, in the XY plane, which is composed of the X-axis direction parallel to the first optical axis O_71 of the first optical system 700 and the Y-axis direction parallel to the lens mount central axis O_3, the first optical axis O_71 and the lens mount central axis O_3 intersect. Also, in the XY plane, the first optical axis O_81 of the second optical system 800 intersects with the lens mount central axis O_3. As shown in Figure 7, unlike the lens device 1 of the first embodiment, the first optical axes O_71 and O_81 are arranged parallel to each other at a distance G apart, and in the XY plane of Figure 8, the second optical axes O_72 and O_82, and the lens mount central axis O_3 are projected to overlap.

[0027] In Figure 7, the image sensor 900 of the camera body is located inside the lens mount 300, and prisms 720 and 820 are arranged side by side along the longitudinal direction of the image sensor 900.

[0028] In this embodiment, unlike the first embodiment, the first optical system 700 and the second optical system 800 are arranged at a distance G in the Z-axis direction. However, the area in the XY plane where the direction parallel to the optical axis O_71 of the first optical system 700 is the X-axis and the direction parallel to the lens mount central axis O_3 is the Y-axis is the same as in the lens device 1, so the explanation is omitted.

[0029] As shown in Figure 8, the points of maximum field of view of the incident light beam of the first optical system 700 (B71, B72) and the points of maximum field of view of the incident light beam of the second optical system 800 (B81, B82) intersect at point C7 on the lens mount 300 side and at point C8 on the opposite side of the lens mount 300. The nodal point of the first optical system 700 is point A7, and the nodal point of the second optical system 800 is point A8. The lens mount 300 is located within the triangular region formed by points A7, A8, and C7, which is included in the non-shooting area of ​​the lens device 2. In other words, the lens device 2 can shoot with a 360-degree field of view while suppressing reflections of the lens mount 300. [Third Embodiment] In this embodiment, an imaging device 4 having a lens device 2 according to the second embodiment and a camera body 3 to which the lens device 2 can be attached will be described. The imaging device 4 is capable of capturing images with a 360-degree field of view while suppressing reflections of the grip portion that protrudes from the camera body 3 towards the lens device 2.

[0030] Figures 9(a) to 9(c) are perspective views, side views, and side views of the imaging device 4, respectively, showing the external appearance of the imaging device 4. Figure 10 is a diagram illustrating the area of ​​the imaging device 4 that cannot be photographed, and is a side view of Figure 9(c) with the area of ​​the lens device 2 in the XY plane shown in Figure 8 superimposed on it. Figure 11 is a diagram showing the imaging surface of the image sensor 900 of the imaging device 4. The XYZ coordinate system in each figure is the same as in the second embodiment.

[0031] The camera body 3, which is the main body of the imaging device, has a camera mount that corresponds to the lens mount 300, and a grip portion 310 that protrudes toward the lens device 2 and extends in the X-axis direction, which is the shorter direction of the camera body 3.

[0032] As shown in Figure 7, the first optical axis O_71 of the first optical system 700 and the first optical axis O_81 of the second optical system 800 of the lens device 2 are parallel to the X-axis. In the lens device 2, prisms 720 and 820 are arranged along the longitudinal direction of the image sensor 900 located inside the camera body 3. The sensor size and aspect ratio of the image sensor 900 differ depending on the camera body 3. However, in any image sensor 900, by arranging two prisms along the longitudinal direction of the image sensor 900, it becomes possible to arrange two image circles on the imaging surface of the image sensor 900. In Figure 11, the imaging surface of the image sensor 900 has two image circles side by side: image circle P1, which captures the image from the first optical system 700, and image circle P2, which captures the image from the second optical system 800.

[0033] As mentioned above, in Figure 10, the area in the XY plane where imaging is impossible is within the triangular region formed by points A7, A8, and C7. The grip portion 310 is located within this area where imaging is impossible. In other words, the imaging device 4 is capable of capturing images with a 360-degree field of view while suppressing reflections not only from the lens mount 300 but also from the grip portion 310 of the camera body 3.

[0034] Furthermore, by positioning not only the grip portion 310 but the entire camera body 3 in the non-shooting area, it is possible to suppress reflections of the camera body 3 other than the subject. However, if the distance between the nodal points A7 and A8 is widened in order to suppress reflections of the camera body 3, the area in the 360-degree field of view image where the subject is not visible becomes wider, so it is preferable to have a narrower non-shooting area.

[0035] The above describes a lens device and imaging device that enable 360-degree field-of-view shooting while suppressing reflections of elements other than the subject, such as the lens mount 300, the protruding part on the lens side of the camera body 3 (grip part 310), and the camera body 3.

[0036] Furthermore, by using the lens device of each embodiment, images from two optical systems are captured on a single image sensor, making it easy to manage image data covering a 360-degree field of view. For example, it eliminates the need for stitching to obtain a 360-degree image from two images taken from different image sensors, as well as the complex processes of synchronizing the timing and matching the colors of the two images, making it possible to easily generate 360-degree field of view data.

[0037] This embodiment includes the following configuration. (Composition 1) The first optical system and A second optical system arranged in a different orientation from the first optical system, It has a mount that can be attached to the main body of the imaging device, The first optical system and the second optical system each comprise a first optical axis, a bending optical section, and a second optical axis, respectively, from the object side to the image side. The mount is parallel to the second optical axis of the first optical system and the second optical system, and has a central axis passing through the center of the mount. The first optical system includes a first nodal point, which is a node in the path between the light taken in from the first optical system and the interior of the imaging device body. The second optical system includes a second nodal point, which is a node in the path between the light taken in from the second optical system and the interior of the imaging device body. A lens device characterized in that, when projected onto a plane parallel to the first optical axis and the central axis of at least one of the first optical systems and the second optical system, the mount is positioned within a triangular region connecting one of the two points where the maximum angle of view portion of the incident light beam of the first optical system and the maximum angle of view portion of the incident light beam of the second optical system intersect, the first nodal point, and the second nodal point. (Configuration 2) The lens device according to configuration 1, characterized in that the bending optical portion of the first optical system and the second optical system each includes a reflective surface that bends light traveling along the first optical axis in a direction parallel to the second optical axis. (Composition 3) The lens device according to configuration 1 or 2, characterized in that the first optical axis and the second optical axis are orthogonal to each other. (Composition 4) A lens device according to any one of configurations 1 to 3, characterized in that the straight line containing the first optical axis of the first optical system and the second optical system intersects with the central axis. (Composition 5) A lens device according to any one of configurations 1 to 4, characterized in that the first optical axis of the first optical system and the first optical axis of the second optical system are arranged on the same straight line. (Composition 6) A lens device according to any one of configurations 1 to 4, characterized in that the first optical axis of the first optical system and the first optical axis of the second optical system are parallel. (Composition 7) A lens device according to any one of configurations 1 to 6, characterized in that the distance between the second optical axes of the first optical system and the second optical system is shorter than the diameter of the mount. (Composition 8) A lens device described in any one of configurations 1 to 7, An imaging device characterized by having an imaging device body to which the lens device can be attached and which holds one image sensor. (Composition 9) The imaging apparatus according to configuration 7, characterized in that the bent optical section of the first optical system and the bent optical section of the second optical system are arranged along the longitudinal direction of the image sensor. (Composition 10) The imaging device body is provided with a protrusion that protrudes toward the lens device side, The imaging apparatus according to configuration 8 or 9, characterized in that the convex portion is arranged within the region. (Composition 11) The imaging device according to any one of the configurations 8 to 10, characterized in that the imaging device body is arranged within the region. (Composition 12) The imaging apparatus according to any one of configurations 8 to 11, characterized in that the first image formed by the first optical system and the second image formed by the second optical system are formed on the imaging surface of the image sensor along the longitudinal direction of the image sensor.

[0038] Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of its essence. [Explanation of Symbols]

[0039] 1,2 Lens device 100,700 First optical system 200,800 Second optical system 120, 220, 720, 820 prism (refracted optical part) 300 Lens Mount (Mount)

Claims

1. The first optical system and A second optical system arranged in a different orientation from the first optical system, It has a mount that can be attached to the main body of the imaging device, The first optical system and the second optical system each comprise a first optical axis, a bending optical section, and a second optical axis, respectively, from the object side to the image side. The mount is parallel to the second optical axis of the first optical system and the second optical system, and has a central axis passing through the center of the mount. The first optical system includes a first nodal point, which is a node in the path between the light taken in from the first optical system and the interior of the imaging device body. The second optical system includes a second nodal point, which is a node in the path between the light taken in from the second optical system and the interior of the imaging device body. A lens device characterized in that, when projected onto a plane parallel to the first optical axis and the central axis of at least one of the first optical system and the second optical system, the mount is positioned within a triangular region connecting one of the two points where the maximum angle of view portion of the incident light beam of the first optical system and the maximum angle of view portion of the incident light beam of the second optical system intersect, the first nodal point, and the second nodal point.

2. The lens device according to claim 1, characterized in that the bending optical portion of the first optical system and the second optical system each includes a reflective surface that bends light traveling along the first optical axis in a direction parallel to the second optical axis.

3. The lens device according to claim 1 or 2, characterized in that the first optical axis and the second optical axis are orthogonal to each other.

4. The lens device according to claim 1 or 2, characterized in that the central axis intersects with a straight line containing the first optical axis of each of the first optical system and the second optical system.

5. The lens device according to claim 1 or 2, characterized in that the first optical axis of the first optical system and the first optical axis of the second optical system are arranged on the same straight line.

6. The lens device according to claim 1 or 2, characterized in that the first optical axis of the first optical system and the first optical axis of the second optical system are parallel.

7. The lens device according to claim 1 or 2, characterized in that the distance between the second optical axes of the first optical system and the second optical system is shorter than the diameter of the mount.

8. A lens device according to claim 1 or 2, An imaging device characterized by having an imaging device body to which the lens device can be attached and which holds one image sensor.

9. The imaging apparatus according to claim 8, characterized in that the bent optical section of the first optical system and the bent optical section of the second optical system are arranged along the longitudinal direction of the image sensor.

10. The imaging device body is provided with a protrusion that protrudes toward the lens device side, The imaging device according to claim 8, characterized in that the convex portion is arranged within the region.

11. The imaging device according to claim 8, characterized in that the imaging device body is arranged within the area.

12. The imaging apparatus according to claim 8, characterized in that the first image formed by the first optical system and the second image formed by the second optical system are formed on the imaging surface of the image sensor along the longitudinal direction of the image sensor.

Images