JP7191893B2 - Lens device and imaging device - Google Patents

Description

The present invention relates to a lens device and an imaging device capable of stereoscopic photography.

Patent Document 1 discloses a stereoscopic imaging optical system in which two optical systems are arranged in parallel with a predetermined distance (base line length) apart, and two image circles are imaged in parallel on one imaging device. there is The viewer of the video can feel a stronger three-dimensional effect as the base line length increases. In addition, the baseline length at which a natural three-dimensional effect can be felt is determined according to the distance to the object. you get a feeling. If the base line length is longer than this range, the three-dimensional effect is too strong, while if the base line length is shorter than this range, the three-dimensional effect is weak. Changing the baseline length requires moving the two optics closer or farther apart. However, when images of two optical systems are formed side by side on a single image sensor, the images cannot be separated beyond the light receiving range of the image sensor, and on the other hand, the two images cannot be so close that they overlap.

Therefore, in Patent Document 2, by biasing the diaphragms of the optical systems for the right eye and the left eye with respect to each optical axis, the baseline length can be adjusted without moving the positions of the two images arranged on the image pickup device. A variable stereo imaging optical system is disclosed.

Japanese Unexamined Patent Application Publication No. 2012-3022 JP 2012-113281 A

However, the stereoscopic imaging optical system disclosed in Patent Literature 2 cannot change the base line length with the aperture opened. In addition, the range in which the base line length can be changed in this stereoscopic imaging optical system is limited to the range of the open diameter of the diaphragm. In addition, in the stereoscopic imaging optical systems disclosed in Patent Documents 1 and 2, since two independent optical systems are placed in the lens mount, the base length, which is the distance between the two optical systems, needs to be increased. requires a larger lens mount aperture.

The average distance between the human eyes is about 60 to 65 mm, and in order to obtain a more natural three-dimensional effect similar to that of the human eye, it is necessary to use an optical system with the same base line length. However, in order to realize this, it is necessary to increase the diameter of the lens mount to be larger than 60 mm, which increases the size of the lens device and imaging device.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a small-sized lens device and an imaging device capable of appropriately setting a base line length to obtain a natural stereoscopic effect.

A lens device as one aspect of the present invention has a first optical system, a second optical system arranged in parallel with the first optical system, and a lens mount section attachable to a camera body, The one optical system and the second optical system each have a first optical axis, a second optical axis, and a third optical axis in order from the object side to the image side, and the first optical system and the second optical system The distance between the first optical axes of the systems is greater than the diameter of the lens mount section, and the distance between the third optical axes of the first optical system and the second optical system is greater than the lens mount section. in each of the first optical system and the second optical system, a first lens on the first optical axis, a second lens on the second optical axis, and the third optical A third lens is provided on the axis, and in each of the first optical system and the second optical system, at least part of the third lens is arranged on the image side of the flange surface of the lens mount section. It is

An imaging apparatus as another aspect of the present invention includes the lens device and a camera body holding an imaging element.

Other objects and features of the invention are described in the following embodiments.

ADVANTAGE OF THE INVENTION According to this invention, the lens apparatus and imaging device which provide the compact lens device and imaging device which can set a baseline length appropriately and can obtain a natural stereoscopic effect can be provided.

It is a sectional view of a lens device in this embodiment. 1 is an exploded perspective view of an optical system in this embodiment; FIG. 1 is an exploded perspective view of a lens device according to this embodiment; FIG. 1 is an exploded perspective view of a lens device according to this embodiment; FIG. It is a figure which shows the positional relationship of the lens apparatus and image circle in this embodiment. 1 is a schematic diagram of an imaging device according to the present embodiment; FIG. 4 is a schematic diagram of a focus adjustment unit of the imaging device according to the present embodiment; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

The lens device (interchangeable lens) of this embodiment has two optical systems (first optical system and second optical system) arranged in parallel (symmetrically) with each other, and two image circles in one image sensor. are configured to be imaged in parallel. The two sets of optical systems are horizontally aligned with a predetermined distance (baseline length) apart. When viewed from the image side, the image formed by the right optical system (first optical system) is recorded as a video or still image for the right eye, and the image formed by the left optical system (second optical system) is recorded. Records as a video or still image for the left eye. When playing back moving images or still images (videos), by viewing them using a known 3D display or so-called VR goggles, the viewer's right eye sees the right-eye video, and the left eye sees the video. An image for the left eye is displayed. At this time, an image with parallax is projected to the right eye and the left eye depending on the base length of the lens device, so the viewer can obtain a stereoscopic effect. As described above, the lens device of the present embodiment is a lens device for stereoscopic photography capable of forming two images with parallax by the first optical system and the second optical system.

First, the configuration of a lens device (interchangeable lens) 200 according to the present embodiment will be described with reference to FIGS. 1 to 4. FIG. FIG. 1 is a cross-sectional view of the lens device 200 and shows a schematic configuration of a right-eye optical system 201R and a left-eye optical system 201L of the lens device 200. FIG. FIG. 2 is an exploded perspective view of one optical system (one eye portion) of the right eye optical system 201R and the left eye optical system 201L. FIG. 3 is an exploded perspective view of the lens device 200 viewed from the object side. FIG. 4 is an exploded perspective view of the lens device 200 viewed from the image side. In the description from here on, R is added to the end of the reference numerals for the description of the right-eye optical system, and L is added to the end of the reference numerals to the description of the left-eye optical system. Also, descriptions common to both the right-eye optical system and the left-eye optical system do not have R or L at the end of the reference numeral.

The lens device 200 has a right eye optical system (first optical system) 201R and a left eye optical system (second optical system) 201L. The right-eye optical system 201R and the left-eye optical system 201L are two optical systems arranged in parallel (symmetrically) with each other. The right-eye optical system 201R and the left-eye optical system 201L respectively have first optical axes OA1R and OA1L, second optical axes OA2R and OA2L substantially perpendicular to the first optical axis, and optical axes OA2R and OA2L, respectively, from the subject side (object side) to the image side. It has third optical axes OA3R and OA3L substantially parallel to the first optical axis. Here, "substantially orthogonal or substantially parallel" means not only strictly orthogonal or parallel configurations, but also configurations evaluated as being substantially orthogonal or parallel.

The right-eye optical system 201R and the left-eye optical system 201L are arranged along each optical axis with 1st group lenses (first lenses) 210R and 210L, 2nd group lenses (second lenses) 220R and 220L, and 3rd group lenses. It has lenses (third lenses) 230R and 230L. The first group lenses 210R and 210L are arranged on the first optical axes OA1R and OA1L, the second group lenses 220R and 220L are arranged on the second optical axes OA2R and OA2L, the third group lenses 230R and 230L are arranged on the third optical axes OA3R, Located in OA3L.

The right-eye optical system 201R and the left-eye optical system 201L have first prisms (first reflecting surfaces) 211R and 211L and second prisms (second reflecting surfaces) 221R and 221L, respectively. The first prisms 211R and 211L respectively bend the light beams on the first optical axes OA1R and OA1L and guide them to the second optical axes OA2R and OA2L. The second prisms 221R and 221L respectively bend the light beams on the second optical axes OA2R and OA2L and guide them to the third optical axes OA3R and OA3L. Thus, the right-eye optical system 201R and the left-eye optical system 201L are respectively bending optical systems. The first prisms 211R and 211L reflect the light beams on the first optical axes OA1R and OA1L and bend them into the light beams on the second optical axes OA2R and OA2L. The second prisms 221R and 221L reflect the light beams on the second optical axes OA2R and OA2L and bend them into the light beams on the third optical axes OA3R and OA3L.

The right-eye optical system 201R and the left-eye optical system 201L have first group lens holding members 212R and 212L, second group lens holding members 222R and 222L, and third group lens holding members 231R and 231L, respectively. The first group lens holding members 212R and 212L respectively hold the first group lenses 210R and 210L and the first prisms 211R and 211L. Second group lens holding members 222R and 222L respectively hold second group lenses 220R and 220L and second prisms 221R and 221L. Third group lens holding members 231R and 231L hold third group lenses 230R and 230L, respectively.

The right-eye optical system 201R and the left-eye optical system 201L are fixed to a lens base (lens support member) 203, respectively. A lens base 203 is fixed to a lens mount section 202 for connecting the lens device 200 to the camera body 110 . In this embodiment, the outer peripheral portions 231aR and 231aL of the third group lens holding members 231R and 231L are fitted to the circumferential surfaces 203aR and 203aL of the lens base 203 centered on the third optical axes OA3R and OA3L. The second-group lens holding members 222R and 222L of the right-eye optical system 201R and the left-eye optical system 201L are connected to each other via connecting portions 222aR and 222aL provided in the second-group lens holding members 222R and 222L, respectively.

L1 is the distance between the first optical axis OA1R of the right-eye optical system 201R and the first optical axis OA1L of the left-eye optical system 201L, that is, the baseline length. The longer the base length L1, the more stereoscopic the image will be viewed. L2 is the distance between the third optical axis OA3R of the right eye optical system 201R and the third optical axis OA3L of the left eye optical system 201L. φD is the diameter (aperture, mount diameter) of the lens mount section 202 that can be attached to the camera body, and corresponds to the fitting diameter between the lens mount section 202 and the camera mount section 122 . 202F is a flange surface of the lens mount portion 202;

As shown in FIG. 2, the right-eye optical system 201R and the left-eye optical system 201L each have a first-group lens holding member 212 that holds a first-group lens 210. As shown in FIG. The first group lens holding member 212 is fixed by a pressing ring 215 and covered with a dustproof member 216 for preventing dust from entering from above the pressing ring 215 . The 1st group lens 210 is attached to the 1st group lens base 213 via two types of three rollers 214a and 214b so that the inclination decentering of the 1st group lens holding member 212 can be optically adjusted.

The first prism 211 is attached and adhered to the prism base 217 from the direction along the second optical axis OA2. Also, a prism mask 224 is attached to the prism surface of the first prism 211 to block light outside the optical path. The prism base 217 and the first group lens base 213 are screwed together with screws (not shown). The second group lens 220 is attached and adhered to the second group lens holding member 222 from the direction along the second optical axis OA2. The second prism 221 is attached and adhered to the second group lens holding member 222 from the direction along the third optical axis OA3. Also, a prism mask 233 is attached to the prism surface of the second prism 221 to block light outside the optical path.

A diaphragm unit 223 is arranged between the second group lens holding member 222 and the prism base 217 . The prism base 217 is screwed and fixed to the second group lens holding member 222 . A third group lens 230 is held by a third group lens holding member 231 and fixed to a second group lens holding member 222 by screwing.

As shown in FIGS. 3 and 4, the right-eye optical system 201R and the left-eye optical system 201L are fixed to the lens base 203 with screws. Two types of spacers 209a and 209b and a washer 218 are sandwiched between the lens base 203 and each of the two optical systems of the right-eye optical system 201R and the left-eye optical system 201L. By adjusting the respective thicknesses of the spacers 209a and 209b and the washer 218, it is possible to suppress focus fluctuations due to variations in the two left and right optical systems, and adjust the two optical systems so that they are both at the same focus position. .

FIG. 7 is a schematic diagram of the focus adjustment unit of the imaging device 100. As shown in FIG. As shown in FIG. 7, the lens base 203 is fixed to the lens mount section 202 for attachment to the camera mount section 122 of the camera body 110 with a focus flange 204 and a focus ring (operation member) 205 interposed therebetween. The focus ring 205 is a member whose thickness changes like a cam depending on the angle of rotation. By rotating the focus ring 205, the distance between the focus flange 204 and the lens base 203 can be changed.

In this manner, the focus ring 205 is formed with a cam shape having different thicknesses depending on the rotational phase. The right-eye optical system 201R and the left-eye optical system 201L are fixed to a lens base 203, and the lens base 203 moves back and forth when the focus ring 205 is operated. That is, the cam shape of the focus ring 205 is sandwiched between the lens base 203 and the lens mount section 202 , so that the lens base 203 advances and retreats according to the rotation of the focus ring 205 .

With such a configuration, the entire right-eye optical system 201R and left-eye optical system 201L of the lens device 200 can be extended or retracted. That is, by operating the focus ring 205, it is possible to adjust the focus of both the right-eye optical system 201R and the left-eye optical system 201L. Accordingly, focusing can be performed, and the right-eye optical system 201R and the left-eye optical system 201L can be brought into focus at the same time. The right-eye optical system 201R and the left-eye optical system 201L are independently adjustable in focus.

Since the first lens group 210 of the lens device 200 of this embodiment has a larger lens diameter toward the object side, the width direction size of the lens device 200 also expands in a trumpet shape toward the object side. Therefore, when the focus ring 205 is arranged outside the first group lenses of the left and right optical systems, the diameter of the focus ring 205 becomes large. If the outer diameter of the focus ring 205 protrudes below the bottom surface of the camera, it may interfere with the attachment to the tripod. Further, when the optical system is configured with a wide-angle lens such as a fisheye lens, if the focus ring 205 is arranged near the object of the lens device 200, there is a possibility that the hand operating the focus ring 205 will be reflected within the angle of view. On the other hand, when the diameter of the focus ring 205 is large, there are merits that it is easy to transmit the manipulation torque and that the feeling of manipulation is improved, and there are merits that minute manipulation is facilitated.

Therefore, in the lens device 200 of the present embodiment, the focus ring 205 is arranged closer to the image plane than the reflecting surface of the first prism 211, and when viewed along the first optical axis, the reflection of the first prisms 211R and 211L can be seen. Placed so that it overlaps the surface. Also, the focus ring 205 is arranged coaxially with the lens mount section 202 so as to be rotatable. Third group lenses 230 R and 230 L are arranged inside the inner diameter of the focus ring 205 . In this embodiment, the focus ring 205 is arranged at a position overlapping the first prisms 211R and 211L when viewed along the first optical axis. As a result, the focus ring 205 can be made smaller than when the focus ring 205 is placed near the first lens group 210R, 210L, and the outer diameter of the focus ring 205 is prevented from protruding below the bottom surface of the camera body. does not protrude below the bottom surface). In addition, by arranging the focus ring 205 coaxially with the lens mount part 202 and arranging the lens of the third optical axis inside the inner diameter of the focus ring 205, it is possible to secure an operational feeling equivalent to that of a conventional monocular interchangeable lens. can be done.

Note that the focus ring 205 is not limited to a focus adjustment function (an operation member for adjusting the focus), and may be a zoom ring (an operation member for adjusting the angle of view) or an aperture ring (an operation member for adjusting the aperture). It is also possible to replace with an operation ring having the function of In that case, the lens base 203 is fixed directly to the focus flange 204 and the lens mount section 202 without sandwiching the focus ring 205 .

The third group lenses 230R and 230L arranged on the third optical axis OA3 are arranged so as to enter the inside of the flange surface of the camera mount section 122 attached across the flange surface 202F of the lens mount section 202 as well. In particular, when the lens device 200 of this embodiment is used in a mirrorless camera as the camera body 110, unlike a single-lens reflex camera, there is no need for an optical refraction member such as a mirror and an operation space required for raising the mirror. Therefore, it is possible to design the lens device 200 to be more inside the camera body 110 than the flange surface.

Next, the positions of the optical axes of the lens device 200 and the positional relationship between the lens mount section 202 and the image circle on the imaging element 111 of the camera body 110 will be described with reference to FIG. FIG. 5 is a diagram showing the positional relationship between the lens device 200 and the image circle.

Two image circles, a right-eye image circle ICR formed by the right-eye optical system 201R and a left-eye image circle ICL formed by the left-eye optical system 201L, form parallel images on the image sensor 111 of the camera body 110. tie. It is preferable to set the size of the image circles and the distance between the image circles so that the two image circles do not overlap each other as much as possible. For example, consider an area obtained by dividing the light receiving range of the image sensor 111 into left and right halves at the center. It is preferable to set so that the centers of the circles ICL are positioned respectively. The optical system of the present embodiment (the right-eye optical system 201R and the left-eye optical system 201L) is a circular fisheye lens (wide-angle fisheye lens), and the image formed on the imaging plane has a field angle of approximately 180°. It becomes a mirrored circular image, and two circular images are formed on the left and right.

Next, with reference to FIG. 6, the configuration of the imaging device according to this embodiment will be described. FIG. 6 is a schematic diagram of the imaging device 100. As shown in FIG. The imaging device 100 can capture a stereoscopic image. The imaging device 100 has a camera body 110 and a lens device 200 . The lens device 200 is an interchangeable lens that can be attached to and detached from the camera body 110 . However, the present invention is not limited to this, and can also be applied to an imaging device in which the camera body 110 and the lens device 200 are integrated.

The lens device 200 has a right-eye optical system 201R, a left-eye optical system 201L, and a system controller (lens system controller) 227 . The camera body 110 includes an image sensor 111 , an A/D converter 112 , an image processing section 113 , a display section 114 , an operation section 115 , a storage section 116 , a system control section (camera system control section) 117 , and a camera mount section 122 . have When the lens device 200 is attached to the camera mount section 122 of the camera body 110 via the lens mount section 202, the system control section 117 of the camera body 110 and the system control section 227 of the lens device 200 are electrically connected.

The image of the subject is a right-eye image (first image) formed via the right-eye optical system 201R and a left-eye image (second image) formed via the left-eye optical system 201L side by side. An image is formed on element 111 . The imaging device 111 converts the formed image of the subject (optical signal) into an analog electrical signal. The A/D converter 112 converts the analog electrical signal output from the imaging device 111 into a digital electrical signal (image signal). The image processing unit 113 performs various image processing on the digital electric signal (image signal) output from the A/D converter 112 .

The display unit 114 displays various information. The display unit 114 is realized by using an electronic viewfinder or a liquid crystal panel, for example. The operation unit 115 has a function as a user interface for the user to give instructions to the imaging device 100 . Note that when the display unit 114 has a touch panel, the touch panel also constitutes one of the operation units 115 . The storage unit 116 stores various data such as image data subjected to image processing by the image processing unit 113 . Storage unit 116 also stores programs. Storage unit 116 is realized by using, for example, ROM, RAM, and HDD. The system control unit 117 centrally controls the entire imaging apparatus 100 . The system control unit 117 is realized by using a CPU, for example.

For example, the size of the image pickup device 111 (sensor size) is 24 mm long x 36 mm wide, the diameter of the image circle is φ17 mm, the distance between the left and right third optical axes OA3 is 18 mm, and the length of the left and right second optical axes OA2 is 18 mm. 21 mm. If the right-eye optical system 201R and the left-eye optical system 201L are arranged so that the second optical axis OA2 extends horizontally, the base line length L1 is 60 mm, which is approximately equal to the interpupillary distance of an adult. Also, the diameter ΦD of the lens mount portion 202 can be made shorter than the base line length L1. Further, by making the distance L2 between the left and right third optical axes OA3 shorter than the diameter ΦD of the lens mount section 202, the third group lenses 230R and 230L on the third optical axis OA3 are positioned inside (inside) the lens mount section 202. perimeter).

Thus, in this embodiment, the distance (base line length L1) between the first optical axes OA1R and OA1L of the two optical systems is longer than the diameter φD of the lens mount section 202, and the third optical axis of the two optical systems A distance L2 between OA3R and OA3L is shorter than the diameter φD of the lens mount section 202. FIG. Preferably, in each of the two optical systems, the third lens (third group lens 230) is all arranged within the diameter of the lens mount section. More preferably, in each of the two optical systems, at least part of the third lens is arranged closer to the image side than the flange surface 202F of the lens mount section. Moreover, preferably, in each of the two optical systems, the second optical axis is arranged closer to the object side than the flange surface 202F of the lens mount portion.

According to the present embodiment, it is possible to provide a compact lens device and an imaging device that can appropriately set the base length and obtain a natural stereoscopic effect.

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 the gist.

200 lens device 201R right eye optical system (first optical system)
201L left eye optical system (second optical system)
202 Lens mount parts OA1R, OA1L First optical axes OA2R, OA2L Second optical axes OA3R, OA3L Third optical axis L1 Base line length (distance between first optical axes)
L2 Distance between third optical axes ΦD Diameter of lens mount

Claims (14)

a first optical system;
a second optical system arranged in parallel with the first optical system;
and a lens mount that can be attached to the camera body,
The first optical system and the second optical system each have a first optical axis, a second optical axis, and a third optical axis in order from the object side to the image side,
The distance between the first optical axes of the first optical system and the second optical system is longer than the diameter of the lens mount section, and the third optical axis of the first optical system and the second optical system the distance between is shorter than the diameter of the lens mount,
In each of the first optical system and the second optical system, a first lens is provided on the first optical axis, a second lens is provided on the second optical axis, and a third lens is provided on the third optical axis. is provided,
In each of the first optical system and the second optical system, at least part of the third lens is arranged closer to the image side than the flange surface of the lens mount section . The first optical system and the second optical system are bending optical systems each having a first reflecting surface and a second reflecting surface,
the first reflecting surface reflects the light beam along the first optical axis and bends it into the light beam along the second optical axis;
2. The lens device according to claim 1, wherein the second reflecting surface reflects the light beam on the second optical axis and bends it into the light beam on the third optical axis. 3. The lens device according to claim 1, wherein said third optical axis is parallel to said first optical axis. 4. The lens device according to claim 1, wherein said second optical axis is orthogonal to said first optical axis. 5. In each of said first optical system and said second optical system, said third lens is arranged within a range of a diameter of said lens mount section . The lens device according to . 6. In each of said first optical system and said second optical system, said second optical axis is disposed closer to the object side than a flange surface of said lens mount portion. 1. The lens device according to claim 1. 7. The lens device according to claim 1 , wherein said first optical system and said second optical system are arranged symmetrically. 8. The lens device according to any one of claims 1 to 7 , wherein the lens device is a lens device for stereoscopic photography capable of forming two images having parallax by the first optical system and the second optical system. The lens device according to the paragraph. 9. The lens device according to claim 1 , wherein each of said first optical system and said second optical system is a wide-angle fisheye lens. 10. The lens device according to any one of claims 1 to 9 , wherein each of said first optical system and said second optical system is a circular fisheye lens. a lens device according to any one of claims 1 to 10 ;
An imaging apparatus comprising: a camera body that holds an imaging element. 11. The imaging device is a single imaging device that forms a first image formed by the first optical system and a second image formed by the second optical system in parallel. The imaging device according to . 13. The imaging apparatus according to claim 11 , wherein the lens device is detachable from the camera body. 11. The lens device according to any one of claims 1 to 10, wherein the first optical system and the second optical system can be focused simultaneously.

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