JP2006011103A - Spherical mirror imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize an imaging apparatus capable of increasing the depth of a field, excellent in linearity based on a field angle, and capable of reducing manufacturing costs. <P>SOLUTION: In the spherical mirror imaging apparatus provided with a supporting member for oppositely arranging a spherical mirror having a convex spherical surface or a concave spherical surface and a camera and capable of picking up an image reflected by the spherical mirror by the camera, the supporting member has an approximately elliptical outer edge part. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

    The present invention relates to a spherical mirror imaging apparatus including a spherical mirror having a convex spherical surface or a concave spherical surface and a camera that captures an image reflected from the spherical mirror.

  As prior art documents related to an omnidirectional imaging apparatus in which an object image reflected on an omnidirectional mirror having a hyperboloidal mirror is incident on an imaging camera composed of a lens system and an image sensor, there are the following.

JP 11-174603 A

  A 360-degree horizontal omnidirectional image with no viewing angle restriction is incident on an omnidirectional mirror having a hyperboloid, and the image reflected on this mirror is incident on an imaging camera including a lens system and an image sensor such as a CCD or CMOS. The omnidirectional imaging device is being developed in various fields such as monitoring and mobile robot mounting.

  FIG. 25 is a perspective view showing the configuration of the omnidirectional imaging apparatus disclosed in Patent Document 1. As shown in FIG. Reference numeral 1 denotes a hyperboloid mirror having a hyperbolic conical convex surface, which images an image of the object 2 to be imaged in all directions, condenses the reflected light on the lens system 3, and forms it on the sensor surface of the image sensor 41 of the camera 4. .

  Reference numeral 5 denotes a cylindrical glass support, which has a hyperboloid mirror 1 and a camera 3 arranged to face each other. Reference numeral 6 denotes a center needle, which is formed to extend downward from the convex vertex of the omnidirectional mirror 1 so as to coincide with the optical axis, and prevents the influence of internal reflection of the cylindrical glass support 5.

  FIG. 26 is an example of a research prototype using a glass sphere having a predetermined thickness as a member for connecting a hyperboloid mirror and a camera. When a glass sphere is used as the coupling member, there is an advantage that there is no need to provide a center needle as shown in FIG.

A conventional imaging device using a hyperboloid mirror having a convex curved surface has the following problems due to the optical properties peculiar to the hyperboloid mirror.
(1) The depth of field cannot be obtained, and it is difficult to focus on the entire screen.
(2) There is a large difference in image resolution between an object incident at a position far from the vertex of the mirror bottom surface of the hyperboloid mirror and an object incident at a position near the vertex, which restricts a practical angle of view.
(3) The hyperboloid mirror has a high required accuracy for spherical processing, and has a problem in terms of manufacturing cost.

  FIG. 21 is an optical schematic diagram showing the result of calculating the position of a virtual image of a hyperboloid mirror having a convex curved surface. A dotted line 1 ′ is a virtual hyperboloidal mirror corresponding to the hyperboloidal mirror 1 (when the object position is infinitely greater than the mirror). A virtual image of the object to be imaged can be formed on this line, and this virtual image is captured by the camera 4. Will do.

  A virtual image of the object 2a incident at a position far from the mirror vertex is shown as 2a ', and a virtual image of the object 2b incident at a position near the mirror vertex is shown as 2b'. Although a virtual image can be formed at a position where both an object far from the vertex and a nearby object are almost close, the change of the virtual curved mirror 1 ′ is steep, so that the center and the periphery of the mirror are considerably different. In an example in which the angle of view is designed to be 105 degrees (the elevation angle is 15 degrees), the difference in virtual image position is about 50 mm.

  Assuming that the depth of field of the camera 4 using the image sensor 41 in which 1000 × 1000 pixels of 5.2 μ square are arranged and using a lens system with a focal length f = 8 mm is an aperture F = 1, At a position 120 mm from the principal point, the depth is 3.3 mm (here, the depth of field is defined by a shift equivalent to one pixel).

  Therefore, when trying to focus on the whole, it must be reduced to F = 15 or more. This is not practical even when taking a still image because it requires a long exposure in the room. It is not suitable for capturing moving images that capture 10 to 30 frames per second.

  When the angle of view is increased to 135 degrees (elevation angle 45 degrees), the characteristics are further deteriorated. In this case, since the difference in the position of the virtual image is about 98 mm, it is necessary to narrow down to F = 30 in order to adjust the overall focus, and it is not practical for still images or moving images. The linearity of the angle of view also deteriorates considerably.

  FIG. 23 is a hyperboloid mirror display characteristic diagram. This characteristic indicates a display characteristic when an object having an incident angle of 15 degrees in each of up, down, left, and right is assumed 90 degrees (horizontal position) from the bottom surface of the mirror, and the incident position changes from the bottom surface to the upper end of the mirror. Numbers 15 to 135 indicate angles from the bottom surface (incident light field angle).

  The display height in the radial direction indicates the position in the radial direction of the circumferential display screen, and the maximum corresponds to the outer diameter R of the display screen. (The 90-degree position is 1). The height in the circumferential direction indicates a height corresponding to 15 degrees in the circumferential direction. At the outermost periphery, 2πR / (360 ° / 15 °). As a circular display screen, this 15-degree display is ideally close to a square at each position, and ideally has the same area.

  The hyperboloidal mirror displays a substantially square shape at each position, but the area is greatly different. This shows that the central part has an extremely small area compared to the peripheral part, and the amount of information in this part is small. The aspect ratio of the displayed image is displayed close to 1 at around 0 degree and around 135 degree, but the area is about 30 times different even for patterns of the same size.

  For this reason, when the whole body of a person is imaged, an image with an enlarged head is displayed. As the angle of view increases, the area occupied by it increases rapidly, and the others become relatively small, so a large angle of view cannot be obtained.

  In an omnidirectional camera, a circular image is often developed and displayed as a planar image by computer processing. In this case, a good image is displayed near 135 degrees, and a good image is displayed. There are few and it becomes a very rough display.

  Since the hyperboloidal mirror has a special shape, an NC processing device using a diamond tool for high-precision mirror processing is required for the processing. Furthermore, it is necessary to prepare various mirrors depending on the application. Mirrors with different parameters are required for each mirror size and angle of view (elevation angle), and each mirror is designed and processed in different conditions, resulting in higher manufacturing costs.

  Therefore, the problem to be solved by the present invention is to realize an imaging apparatus that can take a large depth of field, is excellent in linearity by an angle of view, and is low in manufacturing cost.

In order to achieve such an object, the configuration of the present invention is as follows.
(1) In a spherical mirror imaging device that provides a spherical mirror having a convex spherical surface or a concave spherical surface and a support member that opposes the camera, and captures an image reflected by the spherical mirror with the camera.
The spherical mirror imaging device, wherein the support member has a substantially elliptical outer edge.

(2) The spherical mirror imaging device according to (1), wherein the support member is configured by a substantially elliptical transparent arcuate column.

(3) The spherical mirror imaging device according to (2), wherein a joint means is provided at an attachment portion between the arcuate column and the spherical mirror, and the spherical mirror is folded and stored inside the curved side of the arcuate column. .

(4) The spherical mirror imaging device according to (1), wherein the support member is a substantially elliptical transparent sphere having a predetermined thickness.

(5) The spherical mirror imaging device according to (1), wherein the support member is a substantially elliptical transparent solid sphere.

(6) In a spherical mirror imaging device that captures an image reflected by a spherical mirror having a convex spherical surface or a concave spherical surface with a camera,
A planar reflecting member disposed opposite to the spherical mirror having an opening formed at the top;
The camera disposed on the back of the spherical mirror;
A spherical mirror imaging apparatus, wherein an image obtained by reflecting the reflected image of the spherical mirror by the planar reflecting member is captured by the camera through the opening.

(7) The spherical mirror imaging device according to (6), comprising a substantially elliptical transparent sphere having a predetermined thickness for connecting the spherical mirror and the planar reflecting member.

(8) The spherical mirror imaging device according to (6), further comprising a substantially elliptical transparent solid sphere connecting the spherical mirror and the planar reflecting member.

(9) The spherical mirror imaging device according to (6), further comprising a transparent cylindrical member having a predetermined thickness for connecting the spherical mirror and the planar reflecting member.

(10) The spherical mirror imaging device according to (6), further comprising a transparent solid cylindrical member that connects the spherical mirror and the planar reflecting member.

(11) The spherical mirror imaging device according to (9) or (10), further including a first light shielding member formed at a peripheral edge of the planar reflecting member.

(12) The spherical mirror imaging device according to any one of (9) to (11), further comprising a second light shielding member formed at a peripheral edge of an opening formed at the top of the spherical mirror.

(13) The spherical surface according to any one of (6) to (12), wherein an opening is provided in a central portion of the planar reflecting member, and an image of the back surface of the planar reflecting member is captured by the camera. Mirror imaging device.

(14) The spherical mirror imaging device according to (13), wherein a relay lens or a transparent member is incorporated in the opening.

(15) In a spherical mirror imaging device that captures an image reflected by a spherical mirror having a convex spherical surface or a concave spherical surface with a camera,
An apparatus for imaging a spherical mirror, comprising: at least one auxiliary camera for assisting a photographing range of the camera arranged to face the spherical mirror.

(16) The spherical mirror imaging device according to (15), wherein the auxiliary camera is disposed on a back portion of the camera and photographs a back surface portion of the camera.

(17) The spherical mirror imaging device according to (15), wherein the auxiliary camera is disposed on a back portion of the spherical mirror and photographs a back surface portion of the spherical mirror.

(18) The spherical mirror imaging device according to (17), wherein the auxiliary camera is a fish-eye lens camera.

(19) The spherical mirror imaging device according to any one of (15) to (18), further comprising an image processing device that fits and combines the captured image of the camera and the captured image of the auxiliary camera.

(20) In a spherical mirror imaging device that captures an image reflected by a spherical mirror having a convex spherical surface or a concave spherical surface with a camera,
A spherical mirror imaging apparatus, wherein a display for displaying an image captured by the camera is disposed on the rear surface of the spherical mirror.

(21) In a spherical mirror imaging device that captures an image reflected by a spherical mirror having a convex spherical surface or a concave spherical surface with a camera,
A first camera that captures an image reflected from the first spherical mirror;
A second camera that picks up an image reflected from a second spherical mirror that is arranged close to the first spherical mirror back to back and whose reflecting surface is oriented in the opposite direction;
A spherical mirror imaging device comprising:

(22) The spherical mirror imaging device according to (21), further comprising an image processing device that fits and combines the image captured by the first camera and the image captured by the second camera.

(23) One of the first spherical mirror and the second spherical mirror is a spherical mirror having a convex spherical surface, and the other is a spherical mirror having a concave spherical surface (21) or (22) The spherical mirror imaging device described in 1.

(24) The supporting member for arranging the spherical mirror and the camera to face each other has a pair of planar side portions, and an inclination in which an extension of both side surfaces coincides with the optical axis of the spherical mirror is formed. The spherical mirror imaging device described in any one of (15) to (23).

As is apparent from the above description, the present invention has the following effects.
(1) The image position distribution by the spherical mirror is narrow, and the focus of the imaging system is well suited to the entire screen.
(2) Imaging with sufficiently good characteristics can be performed with a wide imaging angle of view of 0 to 135 degrees.
(3) The processing of the spherical mirror is relatively easy, and the manufacturing cost can be reduced as compared with the hyperboloidal mirror.

  Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 to FIG. 20 show images of image processing in a series of embodiments of a spherical mirror imaging apparatus to which the present invention is applied. The same elements as those of the conventional apparatus described with reference to FIG. Hereinafter, the characteristic part of the present invention will be described.

  Prior to the description of the embodiments, the characteristics of the spherical mirror used in the present invention will be described. Here, a true spherical mirror will be described, but an elliptical or short elliptical mirror slightly expanded or compressed in the axial direction is also included. In some cases, such an elliptical sphere can be naturally produced by a manufacturing method. In some cases, it is actively manufactured and used to improve specific characteristics.

  FIG. 22 is an optical schematic diagram showing the result of calculating the position of the virtual image of the spherical mirror having a convex curved surface. A dotted line 10 ′ is a virtual spherical mirror corresponding to the spherical mirror 10, and a virtual image of the imaged object is formed on this line, and the virtual image is captured by the camera 4. A virtual image of the object 2a incident at a position far from the mirror vertex is shown as 2a ', and a virtual image of the object 2b incident at a position near the mirror vertex is shown as 2b'.

  The object assumes the position of ∞ from the mirror surface. The angle of view is 0 to 135 degrees. In the convex spherical mirror, the virtual image is in the width of about 0.3R. Since a spherical mirror having a sphere diameter of 100 mm has R = 50 mm, the width of the image position is 15 mm. In the case of a concave spherical mirror, a real image is obtained. When the angle of view is 0 to 90 degrees, all real images are in the width of about 0.2R, and the width of the image position where R = 50 mm is 10 mm.

  If this is imaged by the same camera as the above-mentioned hyperboloidal mirror, the depth of field is 3.3 mm when the aperture is F = 1. Therefore, the aperture is F = 3 for the concave spherical mirror and F for the convex spherical mirror. = 4.5 is sufficient. The open value of the digital camera or a level that is reduced by 2 to 3 steps is sufficient, and the image can be captured with a high-speed shutter, and moving image shooting is also possible. If the aperture is further reduced by one or two steps, imaging with a high resolution camera can be performed.

  In the spherical mirror, an object far from the apex and an object in the vicinity can form an image at a nearly close position, but since the change of the virtual curved mirror 10 'is gentle, the image position spreads little at the center and the periphery of the mirror, and the object is covered. Since the depth of field is deep, there is a merit that the entire in-focus image can be obtained even with an open aperture.

  FIG. 24 is a spherical mirror display characteristic diagram. The measurement conditions are the same as those of the hyperboloid mirror described in FIG. When a spherical mirror is used in an omnidirectional camera for circular display, the aspect ratio of a square pattern display image is approximately 0 degrees, and when 1 is approximately 135 degrees, a horizontally long screen is displayed that is approximately seven times the height. Although the center portion has a substantially square display and a large area, the peripheral portion has a horizontally elongated display that is shrunk in the radial direction.

  However, there is little difference in the area of patterns of the same size, and an image with almost uniform image quality is obtained on the entire screen by image processing, and it is easy to restore it to a shape close to a square. In other words, since it is horizontally long, there is little area reduction and there is an amount of information, so that a natural good image can be taken as it is at the center (bottom), and a good image can be restored by image processing at the peripheral (side). A device can be realized. In addition, there is an advantage that the incident angle of view can be increased.

  Processing of the spherical mirror is relatively easy, and high-precision spherical processing can be realized with a simple apparatus. Processing methods include plastic plate heating and pressure molding, mold forming, metal plate spatula drawing, mold forming, plastic material, metal material cutting, glass material polishing, etc. A mirror material such as nickel or chromium is formed by plating, vapor deposition, sputtering, or the like. In order to obtain a more accurate spherical mirror, polishing may be performed, and this apparatus can be realized with a simple apparatus.

  The shape of the spherical surface is uniquely determined by its diameter (radius R). Even when an imaging device with a fixed focus lens is used, the angle of view of the imaging range can be adjusted by changing the distance between the mirror and the imaging device lens principal point. What is necessary is just to prepare several types of mirrors with different R depending on the application.

  In the case of a hyperboloid mirror, the center axis of the hyperbola and the main axis of the imaging camera need to be aligned with high precision, and it is necessary to mount the mirror so that the mirror does not tilt. In the case of a spherical mirror, it is sufficient that the imaging camera faces the center of the spherical surface, and the tilt of the mirror is not a problem.

  The spherical mirror includes a convex spherical mirror whose surface is a mirror and a concave spherical mirror whose rear surface is a mirror, both of which can be used in an imaging device. The virtual spherical mirror is a virtual image in the case of a convex spherical mirror and a real image in the case of a concave spherical mirror.

  The present invention provides a specific configuration of an imaging apparatus that employs a spherical mirror having various practical advantages over a hyperboloidal mirror, and FIGS. An embodiment shown in FIG.

  A feature common to the configurations of the first to fifth aspects resides in the shape of a support member that couples the spherical mirror and the camera, and the support member has a substantially elliptical outer edge. When supporting a spherical mirror, there is no influence of internal reflection if it is supported by a transparent body that always has a plane perpendicular to the incident light.

  In the case of a hyperboloidal mirror, only an incident light that is incident on a single focal point on the optical axis is imaged. For this reason, the shape of the support member may have a spherical outer edge as shown in FIG. In the case of a spherical mirror, incident light to be imaged is collected at different points on the optical axis.

  The cross section of the transparent body that always has a plane perpendicular to the incident light has a complicated shape, but can be approximated by an ellipse up to a maximum field angle of about 135 degrees. Therefore, if a substantially elliptical transparent sphere is used as a support member, it is possible to capture an image without influence of internal reflection even with an apparatus having a maximum field angle of about 135 degrees.

  For the support member of the spherical mirror, it is simplest to use a rod-like column installed outside the mirror. However, if an opaque body is used for this column, the portion shielded by the column is not imaged. When a rod-shaped transparent support is used, there is an influence of internal reflection.

  FIG. 1 is characterized in that this problem is solved by using a substantially elliptical transparent arcuate column as a support member. A spherical mirror 10 (convex spherical mirror) disposed opposite to the camera 4 incorporating the lens system 3 is obtained by mirror-finishing the surface of a member that coincides with a part of a virtual sphere indicated by a dotted line A, and the upper part is a mirror. It is fixed to the holding member 11.

  Reference numeral 12 denotes a transparent arcuate support column formed of a bar material such as acrylic, and its outer edge is characterized by matching a part of a virtual ellipse indicated by a chain line B containing the virtual sphere A. The upper part of the transparent arcuate column 12 is fixed to the mirror holding member 11, and the lower part is fixed to the housing of the camera 4 via the auxiliary member 13, and the camera 4 and the spherical mirror 10 are fixed to each other by these fixing means. Opposed across the distance.

  By using the substantially elliptical transparent arcuate support 12 as described above, omnidirectional imaging is possible without the influence of internal reflection, but when a shape having both planar opaque both sides is adopted as a support, If the side surface is processed so as to face the central axis of the spherical mirror 10, it is possible to prevent a defect that the side surface is imaged (this technique will be described later in the embodiment of FIG. 20).

  FIG. 2 is characterized in that the basic configuration is the same as that in FIG. 1, but a concave spherical mirror is used as the spherical mirror 10. The concave spherical mirror uses the inside of a spherical body having a predetermined thickness, but can also be realized by forming a spherical concave portion in the lower portion of the mirror holding member 11 and forming a reflective portion on the concave surface by vapor deposition or plating. .

  FIG. 3 is characterized in that the basic configuration is the same as that of FIG. 1, but joint means are provided in the transparent arcuate column and the mirror mounting portion, and the spherical mirror is folded and stored inside the curve of the transparent arcuate column. An auxiliary member 14 parallel to the auxiliary member 13 is fixed to the top of the transparent arcuate column 12, and the auxiliary member 14 and the mirror holding member 11 are coupled via a joint means 15.

  At the time of storage, the spherical mirror 10 and the mirror holding member 11 are rotated 90 degrees in the direction of the arrow R, and are stored in the space on the curved inner side C of the transparent arcuate column 12 as indicated by 10a and 11a. Reference numerals 131 and 132 denote joint means provided at a connecting portion between the auxiliary member 13 and the transparent arcuate column 12 and a connecting portion between the housing of the camera 4.

  By rotating the housing of the camera 4 180 degrees by this joint means and moving it to the lower side of the auxiliary member 13, and further rotating the auxiliary member 13 180 degrees and moving it to the upper part of the mirror holding member 11a, The housing can be housed in the upper part of the mirror holding member 11a. When the camera 4 is smaller than the spherical mirror 10, it is compact as a whole, which is convenient for carrying and storing. In addition, the cover can be easily put on during storage, and dirt can be prevented.

  FIG. 4 is characterized in that a substantially elliptical transparent sphere having a predetermined thickness is used as a support member for opposingly arranging the spherical mirror and the camera. Reference numeral 16 denotes a hollow thin-walled elliptical sphere made of a transparent material such as glass or acrylic, and joins between the peripheral edge of the mirror holding member 11 and the peripheral edge of the hood 42.

  This elliptical transparent sphere has a function as a support member for arranging the spherical mirror 10 and the camera 4 to face each other and a dustproof function for the spherical mirror 10, and has a substantially elliptical shape, so that it has a practical angle of view of 135 degrees. An imaging device that is not affected by internal reflection can be realized.

  5 has the same configuration as that of FIG. 4 using a substantially elliptical transparent sphere having a predetermined thickness as a support member for opposingly arranging the spherical mirror and the camera, but a concave spherical mirror is used as the spherical mirror 10. Features the configuration. The concave spherical mirror 10 can also be realized by forming a spherical concave portion in the lower portion of the mirror holding member 11 and forming a reflective portion on the concave surface by vapor deposition or plating as described with reference to FIG.

  With the concave spherical mirror, a real image is formed on the front surface of the mirror, and it is captured. Therefore, with the concave spherical mirror, incident light exceeding the angle of view of 90 degrees cannot be vignetted and imaged by the edge of the mirror. If the incident field angle is α, the angle from the spherical center of the spherical mirror is β, and the viewing angle of the imaging system is θ, there is a relationship of β = (α + θ) / 2 from the relationship of α = 2β−θ.

  If θ = 15 degrees, in order to set α = 90 degrees, β = 52.5 degrees, and the angle of view is smaller than 90 degrees regardless of whether β is larger or smaller. In practice, the viewing angle of the imaging system is optimized by using a varifocal lens or adjusting the position with the mirror.

  In an imaging device using a concave spherical mirror, by optimizing the shape of the concave mirror according to the incident angle of the imaging system, a wide-angle image of about 90 ° × 2 can be obtained using a concave spherical mirror that can be processed with high accuracy at low cost. Imaging can be performed.

  FIG. 6 is characterized in that a transparent substantially elliptical solid sphere is used as a support member for arranging the spherical mirror and the camera to face each other. Reference numeral 17 denotes a transparent ellipsoid made of a block such as glass or acrylic. A spherical concave portion D is processed at a position where the spherical mirror 10 is arranged, and a mirror surface is formed on the concave surface by vapor deposition or plating, and this is formed into a spherical surface. It functions as the mirror 10.

  By such a manufacturing method, the support member and the spherical mirror can be integrally processed with high accuracy. In this configuration, the dust-proof function for the spherical mirror 10 is essentially unnecessary, and the solid sphere 17 has a substantially elliptical shape, so that a high-accuracy imaging device that is not affected by internal reflection within a practical range of an angle of view of 135 degrees. realizable.

  Next, the characteristic common to the structure of Claims 6 thru | or 14 exists in the structure provided with a folding | turning reflection member. FIG. 7A shows the basic configuration. That is, the spherical mirror 10 is provided with a planar reflecting member 18 disposed opposite to the spherical mirror 10 having the opening 101 formed at the top, and a camera 4 fixedly disposed on the mirror holding member 11 on the back of the spherical mirror 10. The reflected image obtained by folding and reflecting the reflected image by the planar reflecting member 18 is captured by the camera 4 through the opening 101.

  The 18-plane reflecting member may be a perfect plane in principle, but may have some aspects for improving optical characteristics.

  Reference numeral 19 denotes a holding member for the planar reflecting member 14, and 20 denotes an auxiliary member coupled to the holding member 19. The planar reflecting member 18 is held at a position facing the spherical mirror 10. Reference numeral 21 denotes a connecting member that connects the auxiliary member 20 and the mirror holding member 11, and restricts the relative positional relationship of the planar reflecting member 18 with the spherical mirror 10.

  Such a configuration using the planar reflecting member 18 has a short structure because the optical path is folded back, and there is an advantage that the entire imaging device can be downsized, and an angle of view of about −45 to +60 degrees is obtained, which is practical. However, an image formed by the planar reflecting member 18 is blind.

  In order to solve this problem, an opening 22 that penetrates the central portions of the planar reflecting member 18 and the holding member 19 is formed, and this opening is formed as a gap or a transparent body. Structure. If necessary, a relay lens 23 for expanding the angle of view is incorporated here. Reference numeral 24 denotes a hood of the relay lens 23. In addition, although the rod shape was illustrated as the connection member 21, the transparent arcuate support | pillar 12 shown in FIG. 1 may be used.

  FIG. 7B shows an image captured by the camera, which corresponds to an image of a portion where the central image is shielded by the folding mirror. The relay lens is adjusted so that the image of the spherical mirror and the transmitted image can be seen practically without a sense of incongruity, and processing such as enlargement, reduction, and position reversal of the transmitted image portion is performed by image processing. By such optional processing, a compact and inexpensive configuration and a bright imaging device without light attenuation by the cover can be realized.

  8 has the same basic configuration as that of FIG. 7 but is characterized in that the coupling between the mirror holding member 11 and the holding member 19 of the planar reflecting member 18 is configured using the elliptical transparent sphere 16 described in FIG. To do.

  The effect of the elliptical transparent sphere 16 is the same as that of the embodiment of FIG. 4, but the elliptical transparent sphere can be reduced in size by the optical path folding structure, the optical axis direction is shortened, and the overall size is reduced. A 360 ° horizontal omnidirectional sensor provides a field angle of 45 ° depression and 60 ° elevation, and is suitable for applications mainly in the horizontal direction. When installed on a conference table or the like, a person and a table can be well imaged simultaneously.

  9 has the same basic configuration as that of FIG. 7, but is characterized in that the connection between the mirror holding member 11 and the member 19 of the planar reflecting member 18 is made using the elliptical solid sphere 17 described in FIG. .

  The effect of the elliptical solid sphere 17 is the same as that of the embodiment of FIG. 6, but the elliptical transparent sphere can be reduced in size by the optical path folding structure, the optical axis direction is shortened, and the overall size is reduced. A 360 ° horizontal omnidirectional sensor provides a field angle of 45 ° depression and 60 ° elevation, and is suitable for applications mainly in the horizontal direction. When installed on a conference table or the like, a person and a table can be well imaged simultaneously.

  Further, as a method for producing an elliptical solid sphere, a semispherical depression is processed in a transparent ellipsoid made of a block such as glass or acrylic, and a mirror surface is formed here to form a spherical mirror 10, with a reflecting mirror on the opposite surface. By forming the flat reflecting member 18, high-precision processing can be performed.

  FIG. 10 is characterized in that the basic configuration is the same as that of FIG. 7 but includes a transparent cylindrical member having a predetermined thickness as a member for connecting the spherical mirror and the planar reflecting member. Reference numeral 25 denotes a transparent cylindrical member such as glass or acrylic, which couples the mirror holding member 11 and the holding member 19 of the planar reflecting member 18 so that the spherical mirror 10 and the planar reflecting member 18 are opposed to each other with a predetermined distance. .

  Reference numeral 26 denotes a first light shielding member formed at the peripheral edge of the planar reflecting member 18, and reference numeral 27 denotes a second light shielding member formed at the peripheral edge of the opening formed at the top of the spherical mirror 10. By using at least one of these light shielding members, it is possible to shield excess light due to the internal reflection of the transparent cylindrical member, and the center needle employed in the conventional apparatus of FIG. 25 can be eliminated. By using both the first light shielding member and the second light shielding member, a complete light shielding effect can be expected.

  Further, the transparent cylindrical member can be made solid as shown in FIG. As a method of manufacturing a solid cylindrical member, a hemispherical depression is processed in a transparent cylindrical member made of glass or acrylic block, and a mirror surface is formed here to form a spherical mirror 10, and a reflecting mirror is formed on the opposite surface. The planar reflection member 18 is formed, and the first and second light shielding members 26 and 27 are formed with wedge-shaped recesses, and the recesses are filled with an opaque member for high-precision processing. be able to.

  The configuration using the transparent cylindrical member or the cylindrical solid has a merit that the radial direction is small in the cylindrical structure, the optical axis direction is also short, and the whole is small. Furthermore, an image that can shield excess light such as reflected light by the light shielding members provided at two locations can be obtained. As a 360 degree horizontal omnidirectional sensor, an angle of view of about 45 degrees depression angle and 60 degrees elevation angle is obtained, which is suitable for applications mainly in the horizontal direction. When placed on a conference table, people and tables can be captured well at the same time.

  Next, a feature common to the configurations of claims 15 to 20 is that at least one auxiliary camera or display is provided to assist the photographing range of the camera. An embodiment using an auxiliary camera will be described with reference to FIGS.

  In FIG. 11, reference numeral 28 denotes an auxiliary camera, which is arranged back to back on the back of the camera 4 that is disposed opposite to the spherical mirror 10 and is shielded by the camera 4 when the convex spherical mirror 10 is used (dotted line θ). In charge of shooting to compensate for the viewing angle. Reference numeral 29 denotes a camera holding member that supports the camera 4 and the auxiliary camera 28 that are arranged back to back. Reference numeral 30 denotes a connecting member that connects the mirror holding member 11 and the camera holding member 29.

Reference numeral 31 denotes an image processing apparatus, which inputs the image of the camera 4 and the image of the auxiliary camera 28, and synthesizes them with a screen that does not feel uncomfortable by a screen synthesis algorithm. FIG. 12 is an image diagram of screen composition.
The occlusion area generated at the center of the image of the camera 4 shown in FIG. 12A is fitted and synthesized using the captured image of the auxiliary camera 28 shown in FIG.

  As the imaging device using the spherical mirror 10 and the camera 4, it is possible to use devices of other methods shown in FIGS. 1 to 6 in addition to the opposing arrangement by a simple connecting member as shown in FIG. 11. Further, in the structure including the planar reflecting member 18 shown in FIGS. 7 to 10, the same effect can be obtained by providing an auxiliary camera at the position of the relay lens 23 and imaging a portion shielded by the planar reflecting member. can get.

  By introducing an auxiliary camera, a device using a convex spherical mirror can compensate for the portion shielded by the camera and realize an ultra wide-angle imaging device up to 270 degrees ahead where the image of the shielding object is not captured. A similar apparatus using a concave spherical mirror can perform wide-angle shooting up to approximately 90 degrees × 2 without shielding.

  The embodiment of FIG. 13 is characterized in that the auxiliary camera 28 is disposed on the back of the spherical mirror 10 and photographs the back surface of the spherical mirror 10. The auxiliary camera 28 is a wide-angle camera having an angle of view of 90 degrees or more.

  The feature of the embodiment of FIG. 14 is that the spherical mirror 10 is a concave spherical mirror, the auxiliary camera 28 is disposed on the back of the spherical mirror 10, and the back of the spherical mirror 10 is photographed. Here, the auxiliary camera 28 is a fisheye lens camera having an angle of view of 180 degrees or more.

  In the embodiment of FIG. 13 and FIG. 14, the auxiliary camera 28 having a wide angle of view is used to perform horizontal and vertical 360-degree imaging in a super omnidirectional direction, and the non-imaging portion of the camera 4 is captured by the auxiliary camera 28. Complementary form. If necessary, the image processing device 31 is used to perform processing such as combining the images of both cameras using an image processing algorithm.

  FIG. 15 is an image diagram of screen composition. FIG. 15A shows a wide-angle image of the auxiliary camera 28, and the peripheral edge portion is fitted and synthesized with the peripheral edge image of the camera 4 shown in FIG. 15B. Note that the back-to-back apparatus shown in FIG. 11 may be used in place of the camera 4, and in this case, an image of a portion shielded by the camera itself is also obtained.

  When the camera 4 captures an angle of view of 135 × 2 = 270 degrees of the convex spherical mirror, the auxiliary camera 28 only needs to capture an angle of view of 45 × 2 = 90 degrees. 360 degree image information is obtained.

  When the camera 4 images the concave spherical mirror, the field angle is 90 × 2 = 180 degrees. If a fish-eye lens camera is used as the camera 2, there is a model in which the angle of view reaches 92.5 × 2 degrees at the maximum, and image information of 360 degrees of celestial spheres can be obtained together.

  Since the auxiliary camera 28 is installed back-to-back with the spherical mirror 10, the condensing points of both are close and the image is not misaligned. Therefore, it is easy to input images from both cameras to the image processing device 31 and perform processing such as composite display.

  A feature of the embodiment of FIG. 16 is a configuration in which a hand display 32 that displays a captured image of the camera 4 is arranged on the back surface of the spherical mirror 10 in the super-wide-angle imaging device of 270 degrees. The photographer 33 located at the back of the spherical mirror 10 has an advantage that the image can be monitored without being reflected on the screen at the time of imaging.

  Next, a feature common to the configurations of claims 21 to 23 is that the two spherical mirrors are back to back, and the embodiment will be described with reference to FIGS. 17 to 19. FIG. 17A is a side view of a super omnidirectional (horizontal, vertical 360 degree) imaging device in which two convex spherical mirrors are back-to-back, and FIG. 17B is a convex spherical mirror used for imaging up to 135 degrees each. It is a side view when limited to only the part to be performed, and there is an advantage that the mirror part can be made small.

  Reference numeral 34 denotes a first spherical mirror, and reference numeral 35 denotes a first camera, which picks up an image reflected from the spherical mirror 34. Reference numeral 36 denotes a second spherical mirror, which is disposed close to the first spherical mirror 34 so as to be back-to-back, and whose reflecting surface is disposed in the opposite direction. Reference numeral 37 denotes a second camera that captures an image reflected from the spherical mirror 36.

  38 is a mirror holding member that holds the first spherical mirror 24 and the second spherical mirror 36 back to back, 39 is a camera holding member that holds the first camera 35, and 40 is a camera that holds the second camera 37. A holding member 41 is a connecting member, which connects the mirror holding member 38 and the camera holding members 39 and 40 and regulates the opposing arrangement relationship between each spherical mirror and each camera.

  The first spherical mirror 34 and the second spherical mirror 36 can be realized by a single global mirror in addition to a configuration in which two convex spherical mirrors face each other in opposite directions. Furthermore, instead of the first camera 35, an apparatus using the auxiliary camera shown in FIG.

  The captured images of the two (or more) cameras are subjected to processing such as image composition by an image processing algorithm using the image processing device 31 as necessary. When the two cameras capture images of up to 135 degrees, the screen information of 45 degrees to 90 degrees overlaps each other, and can be complemented by image processing to obtain a better image.

  The first camera 35 mainly captures a 180-degree image at the front, and the second camera 37 mainly captures a 180-degree image at the back, and both provide high-quality image information of 360 celestial spheres. In this case, if the convex spherical mirror is only a part used for imaging up to 180 degrees, the mirror part can be further reduced in size.

  FIG. 18 is an image diagram when images of two cameras are combined by image processing. An image from 45 degrees to 90 degrees of the first camera image shown in FIG. 18A is supplemented to the second camera image shown in FIG. 18B, and conversely from 90 degrees of the second camera image. The first camera image is supplemented with an image up to 135 degrees.

  When images from two cameras are combined with each other by image processing, the alignment is important. Image processing can be easily performed by placing a mark 42 on the back-to-back portions of the two mirrors and capturing the image with both cameras. The mark is imaged outside the circular screen at a position that does not interfere with the circular screen.

  A feature of the embodiment shown in FIG. 19 is that one of the first spherical mirror and the second spherical mirror arranged back to back is a spherical mirror having a convex spherical surface, and the other is a spherical mirror having a concave spherical surface. is there. An apparatus using the auxiliary camera shown in FIG. 11 may be used in place of the first camera 35 and the second camera 37 that capture images reflected by these spherical mirrors.

  Reference numeral 34 denotes a first spherical mirror having a convex spherical surface, and 36 denotes a second spherical mirror having a concave spherical surface. These spherical mirrors can simultaneously realize concave and convex mirrors on both sides by mirror-treating both sides of one thin sphere. In this apparatus, the condensing points of both are close and the image is not misaligned.

  By imaging using the concave spherical mirror 36, wide-angle imaging up to approximately 90 degrees × 2 can be performed. In the imaging using the convex mirror 34, an imaging range of more than 90 degrees × 2 and 135 degrees × 2 can be easily realized. By combining the images with the image processing device 31, it is possible to realize an omnidirectional super omnidirectional imaging device with 360-degree sky.

  A design example in the case where the images of the two rugged surfaces at 45 degrees of the spherical surface are coincident is shown. Assuming that the viewing angles of both cameras here are equal to θ, it is possible to image up to (90 ° −θ) × 2 with the concave mirror and (90 ° + θ) × 2 with the convex mirror, and 180 ° × 2 in total. Spherical imaging is possible. Actually, various designs are possible without being limited to this combination of conditions.

  When the concave / convex mirror surface is actually made using one spherical surface, the mirror surfaces have slightly different diameters, so care must be taken during the design. However, in practice, both diameters may be slightly different. When a mold is used, it is possible to produce an uneven surface with the same diameter. Concave and convex mirrors are manufactured separately, and there is little difference in the focal point even when back to back.

  Next, the structure of claim 24 is characterized in the support member structure for arranging the spherical mirror and the camera to face each other, which is common to claims 15 to 23. That is, the support member for arranging the spherical mirror and the camera so as to face each other has a pair of planar side portions, and an inclination is formed such that the extension of both side surfaces coincides with the condensing point of the spherical mirror.

  The connecting member 21 shown in FIG. 7, the connecting member 30 shown in FIGS. 11 to 18, and the connecting member 41 shown in FIG. 19 function as a support member for opposingly arranging the spherical mirror and the camera. A simple bar may be used in a usage form where the target object is not obstructed by the support member, but the support member enters the imaging range in the omnidirectional imaging device, so even if it is formed of a transparent material, the member It is necessary to have a structure that does not show the side of

  FIG. 20A is a perspective view of the transparent column body 43, which is characterized in that a configuration surface (side surface) is formed radially with respect to the condensing point of the spherical mirror. That is, when viewed from the camera, the right side surface 43a and the left side surface 43b are formed radially so as to face the condensing point S of the spherical mirror.

  FIG. 20B is a perspective view showing another embodiment of the column body. The feature of this embodiment is basically constituted by a hollow column body 44 formed by a right side member 44a and a left side member 44b made of two thin plates arranged opposite to each other.

  The surfaces of the right side member 44a and the left side member 44b are arranged radially so as to face the condensing point of the spherical mirror, like the transparent column 43 in FIG. If it is weak in strength only by this, it may be reinforced by a plurality of reinforcing members 45 to 48 in the middle. The surface of the reinforcing member is attached to be inclined so as to face the condensing point of the spherical mirror.

  FIG. 20 (C) shows an example of a cross-sectional view of the transparent column body 43 and the hollow column body 44, which may be a quadrangular column or an arcuate section, and has a pair of planar side portions and both sides thereof. There is no restriction on the shape as long as the extension of the surface is inclined so as to coincide with the focal point of the spherical mirror.

  The imaging device using the spherical mirror described above is a wide field angle imaging device such as 270 degrees in the front, 360 degrees in the horizontal direction, 360 degrees in the celestial sphere, etc. The conditions are also very different. In addition to objects of normal brightness, indoors have ceiling lighting, outdoors there are very bright parts such as the sky and the sun, and dark parts that are shaded.

  When a standard camera is used, a very bright part is saturated when exposure is adjusted to an object having normal brightness. If the exposure is adjusted to a very bright part, the normal part will become black. In such an application, it is possible to obtain appropriate exposure as a whole by adopting a wide dynamic camera that captures images by nonlinearly compressing a wide range of brightness.

It is a side view which shows embodiment of this invention using the substantially elliptical transparent arcuate support | pillar as a supporting member. In FIG. 1, it is a side view which shows embodiment of this invention which used the concave spherical mirror as a spherical mirror. It is a side view which shows embodiment of this invention which provided the joint means in the transparent arcuate support | pillar and the mirror attachment part, and folded and accommodated the spherical mirror inside the curve of the transparent arcuate support | pillar. It is a side view which shows embodiment of this invention using the substantially elliptical transparent spherical body which has predetermined | prescribed thickness as a supporting member which arrange | positions a spherical mirror and a camera facing. In FIG. 4, it is a side view which shows embodiment of this invention using the concave spherical mirror as a spherical mirror. It is a side view which shows embodiment of this invention using the elliptical transparent solid spherical body as a supporting member which arrange | positions a spherical mirror and a camera facing each other. It is a side view which shows embodiment of this invention which has the planar reflection member which carries out the reflection reflection of the reflective image of a spherical mirror. It is a side view which shows embodiment of this invention using an elliptical transparent spherical body as a coupling member of a mirror holding member and the holding member of a planar reflective member. It is a side view which shows embodiment of this invention using the elliptical transparent solid spherical body as a coupling member of a mirror holding member and the holding member of a planar reflective member. It is a side view which shows embodiment of this invention which used the transparent cylindrical member as a coupling member of a mirror holding member and the holding member of a planar reflective member. It is a side view which shows embodiment of this invention which has the auxiliary camera arrange | positioned back to back on the back part of the camera arrange | positioned facing a spherical mirror. It is an image figure of the screen composition by two cameras in FIG. It is a side view which shows embodiment of this invention which arrange | positions an auxiliary camera in the back part of a spherical mirror, and image | photographs the back part of a spherical mirror. FIG. 5 is a side view showing an embodiment of the present invention in which the spherical mirror is a concave spherical mirror, a fisheye lens auxiliary camera is disposed on the back of the spherical mirror, and images the back surface of the spherical mirror. FIG. 15 is an image diagram of screen composition by two cameras in FIGS. 13 and 14. It is a side view which shows embodiment of this invention which has arrange | positioned the local display which displays the captured image of a camera on the back surface of a spherical mirror. It is a side view which shows embodiment of this invention which images the super omnidirectional which made two convex spherical mirrors back to back. It is an image figure of the screen composition by two cameras in FIG. FIG. 4 is a side view showing an embodiment of the present invention in which one of the spherical mirrors arranged back to back is a spherical mirror having a convex spherical surface and the other is a spherical mirror having a concave spherical surface. It is the perspective view and sectional drawing which show embodiment of this invention which prevented the influence of internal reflection as a supporting member for arrange | positioning a spherical mirror and a camera facing. It is an optical schematic diagram which shows the result of having calculated the position of the virtual image of the hyperboloid mirror which has a convex curved surface. It is an optical schematic diagram which shows the result of having calculated the position of the virtual image of the spherical mirror which has a convex curve. It is a hyperboloid mirror display characteristic figure. It is a spherical mirror display characteristic figure. It is a perspective view which shows the structure of the omnidirectional imaging device currently disclosed by patent document 1. FIG. It is a side view which shows the product example using the glass bulb | ball which has predetermined thickness as a member which couple | bonds a hyperboloid mirror and a camera.

Explanation of symbols

3 Lens system 4 Camera 41 Image sensor 42 Hood 10 Spherical mirror 11 Mirror holding member 12 Transparent arcuate support 13 Auxiliary member

Claims (24)

In a spherical mirror imaging apparatus that provides a spherical mirror having a convex spherical surface or a concave spherical surface and a support member that opposes the camera, and that captures an image reflected from the spherical mirror with the camera,
The spherical mirror imaging device, wherein the support member has a substantially elliptical outer edge.   The spherical mirror imaging apparatus according to claim 1, wherein the support member is configured by a substantially elliptical transparent arcuate column.   3. The spherical mirror imaging device according to claim 2, wherein joint means is provided at an attachment portion between the arcuate support and the spherical mirror, and the spherical mirror is folded and stored inside the curved support of the arcuate support.   The spherical mirror imaging device according to claim 1, wherein the support member is a substantially elliptical transparent sphere having a predetermined thickness.   The spherical mirror imaging device according to claim 1, wherein the support member is a substantially elliptical transparent solid sphere. In a spherical mirror imaging device that captures an image reflected by a spherical mirror having a convex spherical surface or a concave spherical surface with a camera,
A planar reflecting member disposed opposite to the spherical mirror having an opening formed at the top;
The camera disposed on the back of the spherical mirror;
A spherical mirror imaging apparatus, wherein an image obtained by reflecting the reflected image of the spherical mirror by the planar reflecting member is captured by the camera through the opening.   The spherical mirror imaging device according to claim 6, further comprising a substantially elliptical transparent sphere having a predetermined thickness and connecting the spherical mirror and the planar reflecting member.   The spherical mirror imaging device according to claim 6, further comprising a substantially elliptical transparent solid sphere connecting the spherical mirror and the planar reflecting member.   The spherical mirror imaging device according to claim 6, further comprising a transparent cylindrical member having a predetermined thickness for connecting the spherical mirror and the planar reflecting member.   The spherical mirror imaging device according to claim 6, further comprising a transparent solid cylindrical member that connects the spherical mirror and the planar reflecting member.   11. The spherical mirror imaging device according to claim 9, further comprising a first light shielding member formed at a peripheral edge of the planar reflecting member.   12. The spherical mirror imaging device according to claim 9, further comprising a second light shielding member formed at a peripheral portion of an opening formed at the top of the spherical mirror.   The spherical mirror imaging device according to claim 6, wherein an opening is provided at a central portion of the planar reflecting member, and the planar reflecting member captures an image of a back surface with the camera.   The spherical mirror imaging device according to claim 13, wherein a relay lens or a transparent member is incorporated in the opening. In a spherical mirror imaging device that captures an image reflected by a spherical mirror having a convex spherical surface or a concave spherical surface with a camera,
An apparatus for imaging a spherical mirror, comprising: at least one auxiliary camera for assisting a photographing range of the camera arranged to face the spherical mirror.   The spherical mirror imaging device according to claim 15, wherein the auxiliary camera is disposed on a back portion of the camera and photographs a back surface portion of the camera.   The spherical mirror imaging apparatus according to claim 15, wherein the auxiliary camera is disposed on a back portion of the spherical mirror and photographs a back surface portion of the spherical mirror.   The spherical mirror imaging apparatus according to claim 17, wherein the auxiliary camera is a fisheye lens camera.   The spherical mirror imaging device according to claim 15, further comprising an image processing device that fits and combines a captured image of the camera and a captured image of the auxiliary camera. In a spherical mirror imaging device that captures an image reflected by a spherical mirror having a convex spherical surface or a concave spherical surface with a camera,
A spherical mirror imaging apparatus, wherein a display for displaying an image captured by the camera is disposed on the back surface of the spherical mirror. In a spherical mirror imaging device that captures an image reflected by a spherical mirror having a convex spherical surface or a concave spherical surface with a camera,
A first camera that captures an image reflected from the first spherical mirror;
A second camera that picks up an image reflected by a second spherical mirror that is arranged close to the first spherical mirror back to back and whose reflecting surface is oriented in the opposite direction;
A spherical mirror imaging device comprising:   The spherical mirror imaging device according to claim 21, further comprising an image processing device that fits and combines the captured image of the first camera and the captured image of the second camera.   23. The spherical mirror according to claim 21, wherein one of the first spherical mirror and the second spherical mirror is a spherical mirror having a convex spherical surface, and the other is a spherical mirror having a concave spherical surface. Imaging device. The supporting member for arranging the spherical mirror and the camera to face each other has a pair of planar side portions, and an extension of both side surfaces is formed with an inclination that coincides with the optical axis of the spherical mirror. The spherical mirror imaging device according to claim 15.

Images