JP7590765B2 - Image Rotation System - Google Patents

Description

The present invention relates to an image rotation system that includes a rotation optical system that rotates an image by rotating it, and an adapter used in the image rotation system.

A technique has been proposed in the past in which a rotating optical system such as a Dove prism is rotated by an image rotation device with respect to a rotating imaging target, and the imaging target is imaged by an imaging device while the imaging target is relatively stationary (for example, Non-Patent Document 1). In order to obtain a blur-free still image of a rotating imaging target using such a technique, it is desirable to arrange the rotation axis of the image rotation device that rotates the rotating optical system, the rotation optical axis of the rotating optical system, and the imaging optical axis of the imaging device coaxially, and it is also desirable that they are at least parallel.

"Rotational Blur Cancellation Imaging Using a High-Speed Roll Camera" Journal of the Institute of Image Information and Television Engineers, Vol. 70, No. 9, pp. J209-J214 (2016)

However, in order to align multiple axes, the positions and orientations of the imaging target, the rotating optical system, the image rotation device, and the imaging device must be precisely adjusted, and this adjustment work takes a long time and requires skill.

The present invention has been made in consideration of the above problems, and aims to provide an image rotation system and adapter that can simplify the axial alignment process for acquiring a still image of a rotating imaging target.

In order to achieve the above object, one aspect of the present invention is an image rotation system that includes an image rotation device that rotates a rotating optical system to rotate an image, and an adapter that connects the imaging device and the image rotation device, and the adapter includes an annular imaging side member that is fixed to the imaging device, an annular rotating side member that is fixed to the image rotation device, and a bearing that connects the imaging side member and the rotating side member so that they can rotate relative to each other.

In order to achieve the above object, another aspect of the present invention is an adapter that connects an image rotation device and an imaging device so that the rotation axis of the image rotation device, which rotates a rotating optical system to rotate an image, coincides with the imaging optical axis of the imaging device, which captures the rotating image, and includes an annular imaging side member fixed to the imaging device, an annular rotating side member fixed to the image rotation device, and a bearing that connects the imaging side member and the rotating side member so that they can rotate relative to each other.

According to the present invention, the optical axis of the imaging device and the rotation axis of the image rotation device can be easily aligned, simplifying the axial alignment work of the entire image rotation device and shortening the time required for axial alignment.

1 is a perspective view showing an image rotation system to which an imaging device according to an embodiment is connected; FIG. 2 is an exploded perspective view showing the image rotation system according to the embodiment. 1 is a cross-sectional view of an image rotation system according to an embodiment. FIG. 11 is a cross-sectional view showing another example of the adapter.

The following describes an embodiment of an adapter and an image rotation system including an adapter according to the present invention with reference to the drawings. Note that the following embodiment is an example for explaining the present invention, and is not intended to limit the present invention. For example, the shapes, structures, materials, components, relative positional relationships, connection states, numerical values, mathematical expressions, the contents of each step in the method, and the order of each step shown in the following embodiment are examples, and may include contents not described below. In addition, geometric expressions such as parallel and orthogonal may be used, but these expressions do not indicate mathematical rigor, and include substantially acceptable errors, deviations, etc. In addition, expressions such as simultaneous and identical also include substantially acceptable ranges.

The drawings are schematic diagrams in which emphasis, omissions, or proportions have been appropriately adjusted in order to explain the present invention, and may differ from the actual shapes, positional relationships, and proportions.

In addition, multiple inventions may be collectively described below as a single embodiment. Some of the content described below is also described as an optional component of the present invention.

Figure 1 is a perspective view showing an image rotation system to which an imaging device is connected. Figure 2 is a perspective view showing an exploded image rotation system. Figure 3 is a cross-sectional view of the image rotation system. Note that the cross-sectional view of Figure 3 is simplified by omitting the coils, magnets, bearings, and other components of the motor.

The image rotation system 100 is connected to the imaging device 200 and causes the imaging device 200 to capture an image of a rotating subject in a stationary state. The image rotation system 100 includes a rotation optical system 110 (see FIG. 2), an image rotation device 120, and an adapter 130.

The object to be imaged is not particularly limited. Examples of the object to be imaged include a wheel, a windmill, a waterwheel, a turbine, and other objects in which a rigid body rotates around a fixed axis of rotation. The object to be imaged may also be a fluid. Specifically, the object to be imaged may be a fluid that has been visualized as it passes through a circular or arc-shaped flow path. An example of a visualization process is a process in which particles that emit light when exposed to excitation light or particles that emit light spontaneously (store light) are dispersed in the fluid. Rotation does not only mean rotation in a fixed direction, but may also mean rotation of less than 360° or rotational oscillation within a specified range.

"Taking an image in a stationary state" does not necessarily mean capturing an image of a rotating object as if it were stationary. For example, when it comes to a fluid, the fluid passing through a portion of the flow path is captured in a stationary state, but other portions are not captured in a stationary state. This also includes the meaning of "taking an image in a stationary state."

The imaging device 200 is not particularly limited as long as it can image an image formed by an optical system. The imaging device 200 may be a digital camera, a film camera, or the like. The imaging device 200 may also be a still camera, a video camera, or the like. The imaging device 200 may also image infrared light, ultraviolet light, or the like other than visible light. In the present embodiment, the imaging device 200 is a digital video camera capable of still image capture, and includes an imaging unit 201 having an imaging element arranged perpendicular to the imaging optical axis, and an imaging optical system 202 having a lens, an aperture, and the like. The imaging device 200 is arranged such that the imaging element, the lens, and the like are arranged so as to realize a straight imaging optical axis that passes through the central axis of the imaging optical system 202 and reaches the center of the rectangular imaging element. The imaging optical axis may be bent by a mirror or the like.

Although the imaging device 200 is described as not being included in the image rotation system 100, the imaging device 200 may be included in the image rotation system 100.

The rotating optical system 110 is an optical system that can optically rotate and output an image of an imaging target by physically rotating around the optical axis of the rotating optical system, which is the optical axis of the rotating optical system 110. The type of rotating optical system 110 is not particularly limited, and examples include a Dove prism, an Abbe-Koenig prism, a combination of multiple mirrors, and an acousto-optical Dove prism. In the case of this embodiment, a Dove prism is used as the rotating optical system 110. A Dove prism is composed of a single rigid body, is robust against physical rotation, and the optical axis of the rotating optical system can be easily adjusted.

The image rotation device 120 is a device that physically rotates the rotating optical system 110 to optically rotate the image. The type of image rotation device 120 is not particularly limited, and examples include a device that rotates the rotating optical system 110 using a belt drive mechanism, a gear mechanism, etc. In the case of this embodiment, the image rotation device 120 is a hollow motor, and includes a rotating member 121, a fixed member 122, and a holder 123.

The rotating member 121 is a cylindrical member that holds the rotating optical system 110 therein via a holder 123 and rotates together with the rotating optical system 110 around the optical axis of the rotating optical system. In this embodiment, the image rotation device 120 is a servo motor, and a magnet (not shown) is attached to the outer periphery of the rotating member 121.

In the direction of the rotation axis of the image rotation device 120, the rotating member 121 is longer than the fixed member 122, and both ends of the rotating member 121 protrude from both ends of the fixed member 122. Both ends of the rotating member 121 protruding from the fixed member 122 are provided with screw holes 124 that penetrate in the radial direction and are arranged side by side in the circumferential direction.

A set screw 125, which is a screw that abuts against the outer circumferential surface of the holder 123, is screwed into the screw hole 124. The set screw 125 is a member that generates a force that tightens the rotating optical system 110 via the holder 123 and holds it in the fixed member 122. In addition, by changing the tightening force of the multiple set screws 125, the parallelism and degree of coincidence of the optical axis of the rotating optical system 110 and the rotation axis of the image rotation device 120 can be finely adjusted. In other words, the screw hole 124 provided in the rotating member 121 and the set screw 125 screwed into the screw hole 124 adjust the position and attitude of the holder 123 housed in the rotating member 121 relative to the rotating member 121, thereby adjusting the relationship between the position and attitude of the optical axis of the rotating optical system 110 and the rotation axis of the image rotation device 120, and function as an adjustment attachment means that integrates the rotating member 121 and the rotating optical system 110 via the holder 123.

A sheet made of a polymeric material (not shown) is disposed between the holder 123 and the rotating member 121 on the opposite side of the holder 123 to the set screw 125 in the direction in which the force from the set screw 125, which is the adjustment attachment means, is generated. The polymeric material sheet is, for example, paper, a resin sheet, or a resin film, and preferably has a thickness of 250 μ or less. This makes it possible to disperse the stress generated when the set screw 125 is tightened, and also improves the stability when the rotating optical system 110 is rotated. In particular, these effects can be enhanced by sandwiching a sheet of about 10 μ.

When a Dove prism is used as the rotating optical system 110, the image rotation device 120 is set so that its rotation speed is half the rotation speed of the imaging target. This is because the Dove prism causes the optical rotation of the image to be twice as fast as its physical rotation.

The fixed member 122 is a member that rotatably holds the rotating member 121. In the case of this embodiment, the fixed member 122 is the housing of the hollow motor that is the image rotation device 120, and is attached to the base 127 via a bracket 126. The base 127 extends all the way to the imaging device 200, which is detachable from the base 127. In addition, the posture and height position of the imaging device 200 can be adjusted relative to the base 127.

The adapter 130 has a mechanism for connecting the image pickup device 200, which captures an image that rotates optically due to the physical rotation of the rotating optical system 110, to the image rotation device 120 so that the imaging optical axis of the image pickup device 200 coincides with the rotation axis of the image rotation device 120, and is provided with an image pickup side member 131, a rotation side member 132, and a bearing 133.

The imaging side member 131 is an annular member fixed to the imaging device 200. The imaging side member 131 and the fixing manner to the imaging device 200 are not particularly limited, but in the present embodiment, the imaging side member 131 is fixed to the imaging device 200 by rotating around the rotation axis of the image rotation device 120 with respect to the rotation side member 132 via the bearing 133. Specifically, a female screw with a diameter that surrounds a lens or the like is provided on the tip surface portion of the imaging optical system 202 of the imaging device 200, and a male screw that screws into the female screw of the imaging optical system 202 is provided on the tip portion of the imaging side member 131 on the imaging device 200 side. Even when the adapter 130 is fixed to the image rotation device 120, the imaging side member 131 can rotate via the bearing 133, and the male screw of the imaging side member 131 can be screwed into the female screw of the imaging optical system while rotating to connect and fix the imaging side member 131 and the imaging optical system 202.

If the diameter of the female thread of the imaging optical system 202 does not match the diameter of the male thread of the imaging side member 131, a diameter conversion member (not shown) may be provided that has integrally a first member with a diameter that is attached to the male thread of the imaging side member 131 and a second member with a diameter different from the first member that is attached to the female thread of the imaging optical system 202 of the imaging device 200. This allows the image rotation system 100 to be flexibly applied to multiple imaging devices 200.

The rotating side member 132 is an annular member fixed to the image rotating device 120. The manner in which the rotating side member 132 is fixed to the image rotating device 120 is not particularly limited, but in this embodiment, the rotating side member 132 has a generally cylindrical shape and is fixed to the end face of the fixed member 122 of the image rotating device 120 on the imaging device 200 side. By fixing the rotating side member 132 to the fixed member 122, the rotation axis of the image rotating device 120 and the tube axis of the rotating side member 132 coincide with each other. The manner in which the rotating side member 132 is fixed to the fixed member 122 is not particularly limited, but in this embodiment, the image rotating device 120 has a hole that penetrates parallel to the tube axis, and the end face of the fixed member 122 has a screw hole at a position corresponding to the hole, and is fastened and fixed by a bolt. In addition, the image rotation device 120 and the rotation side member 132 may each be provided with an engagement structure so that the rotation axis of the image rotation device 120 and the tube axis of the rotation side member 132 coincide with each other. For example, an example of the engagement structure is a structure in which multiple pins are provided on one side and pin holes for inserting the pins are provided on the other side.

In this embodiment, the rotating member 132 has a through-hole 134 that penetrates from the fixed member 122 of the rotating member 121 to the adjustment attachment means (screw hole 124, set screw 125) provided in the portion protruding in the inserted state into the adapter 130. The through-hole 134 is a portion for inserting an adjustment tool for adjusting the adjustment attachment means, such as a hexagonal wrench that can rotate the set screw 125. The through-hole 134 penetrates the peripheral wall of the cylindrical rotating member 132 in the radial direction (diameter direction). The shape of the through-hole 134 is not particularly limited, and any shape such as a cylindrical shape surrounded by a periphery or a notched shape as in this embodiment can be adopted. The number of through-holes 134 is not particularly limited, but by providing the through-holes 134 at multiple locations in the circumferential direction, it becomes easier to access the adjustment attachment means without changing the position where the rotating member 121 is stopped.

The bearing 133 connects the annular (cylindrical) imaging side member 131 and the annular (cylindrical) rotating side member 132 so that they can rotate relative to each other. The type of bearing 133 is not particularly limited, and may be either a sliding bearing 133 or a rolling bearing 133. In the present embodiment, a ball bearing is used as the bearing 133. The bearing 133 allows the imaging side member 131 to be screwed and fixed to the imaging optical system 202 of the imaging device 200 while maintaining the tube axis of the imaging side member 131 and the tube axis of the rotating side member 132 coaxially when the rotating side member 132 is fixed to the fixed member 122 of the image rotation device 120.

According to the adapter 130 according to the above embodiment and the image rotation device 120 equipped with the adapter 130, the image capture device 200 and the image rotation device 120 can be easily connected with the rotation axis of the image rotation device 120 aligned with the image capture optical axis of the image capture device 200. Therefore, the time spent on the adjustment work for aligning the rotation axis of the image rotation device 120 with the image capture optical axis of the image capture device 200 can be significantly shortened.

In addition, since the rotation axis of the image rotation device 120 and the optical axis of the rotating optical system 110 can be aligned on the assumption that the rotation axis of the image rotation device 120 and the imaging optical axis of the imaging device 200 coincide with each other, the time required for the alignment can be shortened.

In addition, since it is assumed that the rotation axis of the image rotation device 120 and the imaging optical axis of the imaging device 200 are aligned, the axis alignment work can be performed without rotating the rotating optical system 110, simplifying the work required for axis alignment and reducing the time required.

In addition, the through-hole 134 provided in the rotating member 132 makes it easy to align the rotation axis of the image rotation device 120 with the optical axis of the rotating optical system 110, further shortening the time required for axial alignment.

In addition, by placing a sheet made of a polymeric material such as paper on the portion where force is applied by the adjustment mounting means, the position and attitude of the rotating optical system 110 can be effectively adjusted with respect to the rotation axis of the image rotation device 120, and damage to the rotating optical system 110 due to the force received from the adjustment mounting means can be prevented. Also, the rotating optical system 110 can be rotated in a stable state.

The present invention is not limited to the above-described embodiment. For example, the components described in this specification may be combined in any way, or some of the components may be removed to create another embodiment of the present invention. The present invention also includes modifications that are made to the above-described embodiment by those skilled in the art without departing from the spirit of the present invention, i.e., the meaning of the words in the claims.

For example, in the above embodiment, the imaging side member 131 of the adapter 130 is connected to the imaging device 200 by a screw-in method, but the imaging side member 131 may be fixed to the imaging device 200 by a chuck that moves in a radial direction around the central axis of the adapter 130. Specifically, the imaging side member 131 may have a collet chuck structure.

In addition, the adapter 130 may be attached to the outer circumferential surface of the fixed member 122 of the image rotating device 120, rather than to the end face of the image rotating device 120.

In addition, although the imaging side member 131 has been described as being fixed to the imaging optical system 202, the imaging side member 131 may also be attached to the main body of the imaging device 200.

Also, the adapter 130 may be attached to the rotating member 121 as shown in FIG. 4, instead of to the fixed member 122 of the image rotation device 120. In this case, the bearing 133 of the adapter 130 has a function of allowing the rotating member 121 to rotate relative to the image rotation device 200 while maintaining the optical axis of the image capture device 200 and the rotation axis of the image rotation device 120 coaxially. Even with this type of adapter 130, it is possible to connect the image capture device 200 and the image rotation device 120 with the rotation axis of the image rotation device 120 aligned with the optical axis of the image capture device 200.

The present invention can be used in devices that audit the state of a rotating rigid body or the state of a fluid passing through a flow path in a rotating manner, and detect abnormalities, etc.

REFERENCE SIGNS LIST 100 Image rotation system 110 Rotation optical system 120 Image rotation device 121 Rotation member 122 Fixed member 123 Holder 124 Screw hole 125 Set screw 126 Bracket 127 Base 130 Adapter 131 Imaging side member 132 Rotation side member 133 Bearing 134 Penetration portion 200 Imaging device 201 Imaging section 202 Imaging optical system

Claims (6)

An image rotation system including an image rotation device that rotates a rotation optical system to rotate an image, and an adapter that connects an imaging device and the image rotation device,
The adapter comprises:
an annular imaging side member fixed to the imaging device;
an annular rotating member fixed to the image rotating device;
a bearing that connects the imaging side member and the rotation side member so as to be capable of relative rotation,
The image rotation device includes:
a rotating member that holds and rotates the rotating optical system;
a fixed member that rotatably holds the rotating member,
An image rotation system in which the rotating member is fixed to the fixed member. 2. The image rotation system according to claim 1, wherein the image pickup side member is fixed to the image pickup device by rotating about a rotation axis of the image rotation device. The imaging side member is
3. The image rotation system according to claim 1, further comprising a diameter conversion member integrally having a first member having a diameter to be attached to the imaging side member and a second member having a diameter different from that of the first member to be attached to the imaging device. 2. The image rotation system according to claim 1, wherein the imaging side member is fixed to the imaging device by a chuck that moves in a radial direction around a central axis of the adapter. The image rotation device includes :
A holder for holding the rotating optical system;
The rotating member is cylindrical and has an adjustment mounting means for adjusting the position of the holder housed within the rotating member relative to the rotating member. An image rotation system as described in any one of claims 1 to 4, wherein the rotating side member of the adapter has a through-hole that extends to the adjustment mounting means. The image rotation device includes:
A holder for holding the rotating optical system;
The rotating member is cylindrical, and an adjustment attachment means adjusts the position of the holder housed in the rotating member relative to the rotating member;
6. The image rotation system according to claim 1, further comprising: a sheet made of a polymeric material arranged in a direction in which the force is generated by the adjustment mounting means.

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