Image input device

[0001] The present invention relates to an imaging device in which a number of optical fiber cords are bundled together to form a multiple point structure and a plurality of imaging sections comprised of the structure are radially disposed for omnidirectional imaging, and further, illumination fibers are disposed on the outer periphery of the plurality of imaging sections.

[0002] Conventionally, there have been developed some means as an imaging device for omnidirectional imaging. One of the means is, for example, a reflecting mirror type panorama imaging device shown in FIG. 21(a) in which a reflecting mirror unit 61 as a convex mirror is mounted to the ceiling of a building, an imaging camera unit 62 is disposed just below the reflecting mirror unit 61 and apart a constant distance therefrom, and the camera unit 62 receives images from the reflecting mirror unit 61.

[0003] FIG. 21(b) illustrates an image captured by the camera unit 62 and distorted to an extreme extent.

[0004] Another imaging device for omnidirectional imaging is an extreme wide-angle lens type panorama imaging device shown in FIG. 22(a), in which a camera unit 62 mounting an extreme wide-angle lens unit 63 thereon images an object. Also in this case, an image captured by the camera unit 62 is distorted to an extreme extent, as shown in FIG. 22(b).

[0005] Other than the above-described imaging devices, an imaging device has been developed in which as shown in FIG. 23(a), a camera (not shown) incorporating wide-angle lenses therein is housed in a cubic-shaped box 64 and wide-angle lenses 65a through 65e (wide-angle lenses 65d and 65e are not shown) are projected from side and upper faces of the box 64 to be able to capture omnidirectional images. Although the imaging device constructed as described above acquires images distorted to smaller extent than that observed by using the above-mentioned two imaging devices, i. e., reflecting mirror type and extreme wide-angle lens type imaging devices, the peripheral portion of the acquired image is distorted because of use of wide-angle lens. FIG. 23(b) illustrates an exploded image captured by individual cameras whose field of view is 90 degree in both horizontal and vertical directions, i. e., a square field of view.

[0006] The above-described imaging devices shown in FIGS. 21, 22 each employ means for capturing the omnidirectional images distorted optically to a large extent to complete capture of omnidirectional images by an image capture unit. For this reason, the omnidirectional images captured by the image capture unit image capture unit are distorted to a large extent and therefore, it usually takes an enormous amount of calculation processing to process the distorted images to non-distorted images.

[0007] Furthermore, in the imaging device shown in FIG. 23(a), since a plurality of cameras covers all directions, operation for stitching together individual images captured by the different cameras is required when viewing an entire image or cropping a portion of images corresponding to an arbitrary direction and/or an arbitrary field of view. In this case, since the most distorted peripheral portions of the captured images are stitched together, it also takes an enormous amount of calculation processing to stitch the images together (stitching) and/or compensate for the distortions of the images.

[0008] Moreover, even in the case where a plurality of images captured by multiple cameras are to be stitched together to constitute omnidirectional images, individual cameras each cover a wide field of view and for example, even in the case where eight cameras are employed, the individual cameras each incorporate an extreme wide-angle lens therein whose field of view corresponds to ten-odd millimeters focal length of a lens employed when using a camera that houses a 35 mm film. This makes the images captured by the individual cameras include image distortion peculiar to a wide-angle lens. When blending the omnidirectional images acquired by such devices together, it is required to compensate for distortions of peripheral portions of the images and then, blend the adjacent images together. For this reason, performing the above-mentioned processing requires a large amount of time. Furthermore, every time when cropping arbitrarily a narrow and rectangular portion of the image, it is required to perform conversion of coordinate with respect to the distorted image and then, remove distortion of the image to output the image.

[0009] In order to solve those problems, means for increasing the number of imaging cameras to reduce a field of view per camera has been conceived. However, the following additional problems and drawbacks occur. That is, operation for recording images captured by a plurality of imaging cameras and synthesizing the images at the time of reproduction of images is extremely difficult to be performed and further, the entire scale of device becomes large.

[0010] Moreover, also regarding an imaging illumination, since a regular illumination structure (an illumination light) covers a limited area, such an illumination structure suffers from a large difficulty when providing omnidirectional illumination. Additionally, various attempts to reduce a volume of illumination structure have been facing difficulty.

[0011] In consideration of the above-described problems found in the conventional techniques, the present invention, which is directed to an imaging device having the following constructions to overcome those problems, has been conceived. That is, the imaging device is constructed such that a number of optical fiber cords are bundled together to constitute an imaging section without using a reflecting mirror, an extreme wide-angle lens, etc., while a plurality of imaging sections are radially disposed and non-distorted omnidirectional images consisting of individual forward images, each corresponding to the narrow field of view of the imaging section and obtained by the imaging section, are delivered to an image capture unit. This construction of the imaging device makes it unnecessary to perform calculation processing to compensate for image distortion and makes it possible to construct a small sized camera for capturing omnidirectional images by using only the imaging section formed by bundling a number of optical fiber cords together and the image capture unit. The imaging device is further constructed such that an illumination (light guide) fiber is disposed on an outer periphery of the imaging section to allow even a small sized and omnidirectional imaging camera to radially emit from the plurality of imaging sections strong light rays, which are supplied from outside, through the light guide fiber, thereby enabling the imaging device to capture omnidirectional images under various conditions as well as bright circumstances. The imaging device is still further constructed such that different illumination light rays can individually be supplied to the light guide fiber and operation for capturing omnidirectional images can be performed using periodically emitting light rays in addition to usually-used sequentially emitting light rays.

[0012] The imaging device according to the present invention comprises a multiple point structure constructed by bundling a number of optical fiber cords together, an imaging section formed on one end of the multiple point structure for capturing images, bundling means for bundling a plurality of the multiple point structures together and reading means for reading images using an image pickup device via optical means, the images being captured by the imaging section provided at one end of each of the plurality of the multiple point structures bundled by the bundling means and transmitted to the other end of the each of the plurality of the multiple point structures via the plurality of the multiple point structures, in which the imaging section constitutes one of a plurality of imaging sections with their optical axes being radially disposed.

[0013] As described above, a number of optical fiber cords are bundled together to constitute a multiple point structure, allowing the multiple point structure to capture images though one end thereof. The one end of the multiple point structure is incorporated within and covered by a cylindrical member to constitute one of a plurality of imaging sections.

[0014] The other end of the multiple point structure is incorporated within a rectangular fiber bundling unit to allow an image sensor such as an image pickup device (CCD) to simultaneously read images delivered via optical means. Within the fiber bundling unit are provided a plurality of cylindrical holes in an orderly fashion and in a lattice pattern while passing therethrough. Into the plurality of cylindrical holes are inserted one ends of the plurality of the multiple point structures, the one ends constituting the plurality of imaging sections, and at the same time, all of the one ends of the plurality of the multiple point structures are disposed in the same plane to form a flattened surface.

[0015] Within the imaging section is incorporated an objective lens or a mechanism having a function equivalent to that of the objective lens and the objective lens is supported by a cylindrical member.

[0016] The plurality of imaging sections are radially disposed at 30 degree intervals of latitude and longitude in a sphere-shaped omnidirectional imaging unit.

[0017] Furthermore, on a periphery of the sphere-shaped omnidirectional imaging unit around an equatorial plane thereof are disposed microphones at 60 degree intervals. The microphone is constructed such that it records sound using a multichannel recording method and at the time of reproduction, reproduces the sound in response to change of a direction in which the image is being viewed. Note that the sphere-shaped omnidirectional imaging unit is supportively fixed to a base or the like via a columnar support.

[0018] The images captured by the plurality of imaging sections, which are disposed in the omnidirectional imaging unit, are delivered through the plurality of multiple point structures to the fiber bundling unit and the captured images are obtained on an end face of the fiber bundling unit.

[0019] The images obtained on the end face of the fiber bundling unit are focused onto a surface of an image pickup device as an image sensor via optical means.

[0020] Although the imaging device of the present invention constructed as described above employs a configuration in which whole sky is divided at 30 degree intervals of latitude and longitude, the intervals can be arbitrarily changed. When setting a field of view of the imaging device narrow as described above, the field of view is relatively near the telescopic-side field of view of a standard lens (around 50 mm) of a regular 35-mm camera, advantageously making the captured images distorted to a small extent. This is because the invented imaging device employs a plurality of image fibers and only utilizes images captured through a narrow field of view in front of each of the image fibers to substantially eliminate distortions of images captured by the individual image fibers.

[0021] Furthermore, since imaging operation is performed through a plurality of multiple point structures and one image pickup device, synchronizing the multiple images captured by multiple cameras is not required in the invented imaging device, which operation is required when capturing images using multiple cameras. In addition, the images on a plurality of multiple point structures disposed horizontally are disposed such that the images are delivered to the same horizontal line on the image pickup device. Accordingly, when cropping a portion of images on the image pickup device, reading data corresponding to necessary pixels arranged in horizontal and vertical directions based on location of the portion of images to be cropped makes it possible to blend images located over a necessary geometric range together. This means that operation for blending images together becomes very simple in comparison with that observed in the conventional device.

[0022] For this reason, when viewing the images captured by a plurality of multiple point structures as a blended image, blending the images together becomes very easy. This means that when cropping a portion of the captured omnidirectional images corresponding to an arbitrary direction and/or an arbitrary field of view, the cropping operation advantageously can be performed simply and quickly.

[0023] Simplified cropping operation makes compensation of distortions of individual images unnecessary and further, synchronization of multiple images unnecessary. Moreover, since positional relationship between images to be captured in longitudinal and lateral directions is maintained in longitudinal and lateral directions even on the image pickup device, when cropping a rectangular portion of the captured images, complicated coordinate conversion is not required, thereby reducing the time necessary for cropping.

[0024] It should be noted that when the image pickup device captures the images in a situation where the spherical surface is developed such that the imaging sections on the same longitude are correspondingly disposed in the same longitudinal row in a plane, it becomes possible to view omnidirectional images like a global map. Accordingly, since images to be cropped are identified based on clear positional relationship between the captured images, operation for cropping a portion of the above-described images corresponding to an arbitrary direction and/or an arbitrary field of view can advantageously be performed in a very simple manner.

[0025] As described above, the imaging device constructed in accordance with the present invention is able to easily capture omnidirectional images without distortions of images and even when monitoring the images to be captured, the device is advantageously able to provide high visibility of omnidirectional images and in addition, process the images in an extremely simplified manner even when cropping a portion of images.

[0026] Moreover, the imaging device according to the present invention comprises a multiple point structure constructed by bundling a number of optical fiber cords together, illumination fibers provided on an outer periphery of the multiple point structure, an imaging section provided at one end of the multiple point structure with the illumination fibers for capturing images, bundling means for bundling a plurality of the multiple point structures together, an illumination light ray receiving unit formed by separating the illumination fibers from the bundling means and bundling the illumination fibers together, an illumination light source unit coupled to the illumination light ray receiving unit and provided with a light source for emitting illumination light rays from the illumination fibers, and reading means for reading images using an image sensor via optical means, the images being captured by the imaging section provided at one end of each of the plurality of the multiple point structures separated from the bundling means and transmitted to the other end of the each of the plurality of the multiple point structures via the plurality of the multiple point structures, in which the imaging section constitutes one of a plurality of imaging sections with their optical axes being radially disposed.

[0027] Additionally, the imaging device according to the present invention comprises a multiple point structure constructed by bundling a number of optical fiber cords together, multiple sets of illumination fibers provided on an outer periphery of the multiple point structure for emitting illumination light rays different from one another, an imaging section provided at one end of the multiple point structure with the multiple sets of illumination fibers, bundling means for bundling a plurality of the multiple point structures together, a plurality of illumination light ray receiving units formed by separating the multiple sets of illumination fibers from the bundling means and individually bundling the multiple sets of illumination fibers individually, a plurality of illumination light source units coupled respectively to the plurality of illumination light ray receiving units and individually provided with corresponding light sources for emitting illumination light rays different from one another from the multiple sets of illumination fibers, and reading means for reading images using an image sensor via optical means, the images being captured by the imaging section provided at one end of each of the plurality of the multiple point structures separated from the bundling means and transmitted to the other end of the each of the plurality of the multiple point structures via the plurality of the multiple point structures, in which the imaging section constituting one of a plurality of imaging sections with their optical axes being radially disposed.

[0028] As described above, providing the illumination light source unit in the imaging device allows illumination light rays from the illumination light source unit to be emitted from the distal ends of the imaging sections toward the surroundings. Accordingly, shadow due to the orientation of the illumination light source is never produced and an entire illumination system can be reduced in volume to an extreme extent in comparison with the case where an illumination system includes an illumination light source for providing omnidirectional illumination.

[0029] In addition, when light sources for emitting illumination light rays different from one another are individually provided in the illumination light source unit, strobe light rays from the strobe illumination light source unit for periodically emitting light rays may be supplied in addition to the successively emitting light rays, and further, illumination by infrared rays other than strobe light rays may also be available.

[0030] As described above, the imaging device verifies its extremely high flexibility because it is able to address requirement for use in various applications such as by incorporating strobe light rays as illumination means in addition to regular visible light rays into the device. Furthermore, the imaging device may also be constructed such that during normal operation, infrared light rays for illumination are used to perform supervision or security and at the time of change of images to be displayed, strobe light rays are emitted.

[0031] FIGS. 1(a) to 1(c) generally illustrate a configuration diagram and enlarged views of a first embodiment of the present invention;

[0032] FIGS. 2(a) to 2(e) are a front view, a right side view, a plan view, a cross sectional view and a left side view of an omnidirectional imaging unit;

[0033] FIG. 3 is a general configuration diagram illustrating an entire configuration employed in the first embodiment;

[0034] FIG. 4 is a general configuration provided to explain the theory that the images obtained on the end face of the fiber bundling unit is focused onto an image pickup device;

[0035] FIG. 5 is an explanatory diagram illustrating a situation where the image obtained on the end face of the fiber bundling unit is being focused onto the image pickup device;

[0036] FIG. 6 is an explanatory diagram illustrating a field of view of an image fiber and the field of view thereof used in the embodiment;

[0037] FIG. 7 is a block configuration diagram of a circuitry for converting the images obtained through the imaging sections into an electrical signal within an image pickup device and processing the signal;

[0038] FIGS. 8(a), 8(b), 8(c) respectively illustrate a plan view, a front view and a side view of an omnidirectional imaging unit formed as a regular octahedron;

[0039] FIG. 9 illustrates a perspective view of a fiber bundling unit;

[0040] FIGS. 10(a), 10(b) each illustrate a general configuration diagram of an omnidirectional imaging unit formed as a regular icosahedron;

[0041] FIG. 11 is a general configuration diagram illustrating a layout of images on the image pickup device (CCD);

[0042] FIGS. 12(a) to 12(c) generally illustrate a configuration diagram and enlarged views of a second embodiment of the present invention;

[0043] FIG. 13 is a general configuration diagram illustrating an entire configuration employed in the second embodiment;

[0044] FIG. 14 illustrates a general configuration constructed by adding an illumination light source unit to the configuration shown in FIG. 13;

[0045] FIG. 15 is a general explanatory configuration diagram illustrating the internal configuration of the illumination light source unit;

[0046] FIG. 16 is a block configuration diagram of a circuitry for converting the image obtained through the imaging sections into an electrical signal within an image pickup device and processing the signal;

[0047] FIGS. 17(a) to 17(c) generally illustrate a configuration diagram and enlarged views of a third embodiment of the present invention;

[0048] FIG. 18 is a general configuration diagram illustrating an entire configuration employed in the third embodiment;

[0049] FIG. 19 illustrates a general configuration constructed by adding an illumination light source unit to the configuration shown in FIG. 18;

[0050] FIG. 20 is a block configuration diagram of a circuitry for converting the image obtained through the imaging sections into an electrical signal within an image pickup device and processing the signal;

[0051] FIG. 21 is a general configuration diagram illustrating a reflecting mirror type panorama imaging device as a conventional imaging device for capturing omnidirectional images;

[0052] FIG. 22 is a general configuration diagram illustrating an extreme wide-angle lens type panorama imaging device as a conventional imaging device for capturing omnidirectional images; and

[0053] FIG. 23 is a general configuration diagram illustrating an imaging device for capturing omnidirectional images using a plurality of wide-angle lenses.

[0054] Embodiments of the present invention will be explained with reference to the accompanying drawings.

[0055] FIGS. 1(a) to 1(c) generally illustrate a configuration diagram and enlarged views of a first embodiment of the present invention, and in FIGS. 1(a) to 1(c), a number of optical fiber cords are bundled together to form multiple point structures (hereinafter, referred to as an image fiber) 12a, 12b, 12c . . . for capturing images through one end thereof. As shown in FIG. 1(b), one ends of the image fibers 12a, 12b, 12c . . . each are incorporated within and covered by a cylindrical member 14 to form a plurality of imaging sections 15a, 15b, 15c . . .

[0056] As will be described later, other ends of the image fibers 12a, 12b, 12c . . . each are incorporated within a rectangle-shaped fiber bundling unit 16 to simultaneously read images, which are transmitted through optical means, using an image sensor such as an image pickup device (CCD). As shown in the figure, the fiber bundling unit 16 has a plurality of cylindrical holes 17a, 17b, 17c . . . arranged and formed in a lattice form. Into the cylindrical holes 17a, 17b, 17c . . . are inserted the ends of the image fibers 12a, 12b, 12c . . . , which constitute the imaging sections 15a, 15b, 15c . . . , and at the same time, the end faces of the image fibers 12a, 12b, 12c . . . are adjusted to form the same flattened plane.

[0057] FIG. 1(c) illustrates an enlarged view of each of the imaging sections 15a, 15b, 15c . . . , and an objective lens 13 or a mechanism with a function equal to that of the objective lens is incorporated within each of the imaging sections 15a, 15b, 15c . . . As shown in FIG. 1(c), the objective lens 13 is supportively provided on the cylindrical member 14.

[0058] The above-described imaging sections 15a, 15b, 15c . . . are radially disposed at 30 degree intervals of latitude and longitude in an omnidirectional imaging unit 20 shown in FIGS. 2(a) through 2(e). In addition, on a periphery of the spherical omnidirectional imaging unit 20 around an equatorial plane thereof are formed microphones 21 at 60 degree intervals. The microphone 21 is constructed such that it records sound using a multichannel technique and at the time of reproduction, reproduces the sound in response to change of a direction in which the images are viewed. Note that the omnidirectional imaging unit 20 is supportively fixed to a base or the like, though not shown, via a columnar support 22.

[0059] FIG. 3 is a general configuration diagram illustrating an entire configuration employed in the first embodiment and constructed using the components shown in FIGS. 1 and 2. In FIG. 3, the images captured by the imaging sections 15a, 15b, 15c . . . , which are disposed in the omnidirectional imaging unit 20, are transmitted through the image fibers 12a, 12b, 12c . . . to the fiber bundling unit 16 and the captured images are obtained on an end face of the fiber bundling unit 16.

[0060] FIG. 4 is a general configuration provided to explain the theory that the above-described captured images obtained on the end face of the fiber bundling unit 16 are focused passing through optical means 23 onto surfaces of elements that constitute an image pickup device 24 constructed as an image sensor.

[0061] FIG. 5 is an explanatory diagram illustrating a situation where the images obtained on the end face of the fiber bundling unit 16 are being focused onto the image pickup device and the images on the image pickup device in FIG. 5 are viewed such that a frame portion of the fiber bundling unit 16 is observed as the black portion thereof other than the vacant portion thereof since the end faces of the image fibers 12a, 12b, 12c . . . are arranged in a lattice pattern as shown in the figure. In this construction of the fiber bundling unit 16, making a field of view A (a circle denoted in FIG. 6) of each of the image fibers on the side of the imaging sections 15a, 15b, 15c . . . , which are disposed in the omnidirectional imaging unit 20, wide to make the field of view of one image fiber and the field of view of the other image fiber overlap each other enables the omnidirectional imaging unit to eliminate dead angle. In FIG. 6, an approximately square portion shown in the figure indicates a field of view B that is used in the embodiment.

[0062] It should be noted that since the captured images are obtained on the end face of the fiber bundling unit 16, it is recommended that the radially disposed imaging sections 15a, 15b, 15c . . . and the end faces of the image fibers 12a, 12b, 12c . . . of the fiber bundling unit 16 are disposed to have a predetermined positional and vertical relationship therebetween to make a later performed image processing easily performed.

[0063] The omnidirectional images captured by the imaging sections 15a, 15b, 15c . . . that are constructed as described above are focused via the image fibers 12a, 12b, 12c . . . onto the image pickup device 24. The image pickup device 24 converts those images into an electrical signal and supplies the electrical signal to a signal processing unit 41 shown in the following FIG. 7.

[0064] FIG. 7 is a block configuration diagram of a circuitry for converting the images obtained by the imaging sections. into an electrical signal and processing the signal, and the circuitry is constructed such that the electrical signal from the image pickup device 24 is processed in the signal processing unit 41 and the processed signal is recorded in a recording device 43 via a device interface unit 42 while being supplied to an external processing unit, not shown, via an external interface unit 44.

[0065] It should be noted that although an electrical circuitry subsequent to the signal processing unit 41 may be realized by employing a unit nearly similar to a regular digital image recording unit, the electrical circuitry may also be realized by employing the digital image recording unit while utilizing compression processing or the like as needed to reduce an amount of data.

[0066] Furthermore, as for sound recording, the embodiment may employ a recording method for recording sound from all directions using an omnidirectional microphone or a general stereo recording method. Other than those sound recording methods, the embodiment may employ a sound recording method for previously recording sound on multiple channels using a number of microphones and at the time of reproduction of image, processing a sound signal by means of the signal processing unit 41 to switch channels for sound to be reproduced depending on a direction in which the images are viewed. Note that a power source unit 46 is provided to supply electrical power to the components including the signal processing unit 41.

[0067] As is described so far, although the case where the omnidirectional imaging unit 20 is spherical has been described, FIGS. 8(a), 8(b), 8(c) respectively illustrate a plan view, a front view and a side view of an omnidirectional imaging unit 20 that is formed as a regular octahedron. In the center of equilateral triangles individually constituting planes 20a to 20h (plane 20h is not shown) of the regular octahedron are disposed imaging sections 15a to 15h to be able to capture omnidirectional images. Note that when employing the omnidirectional imaging unit 20 formed as a regular octahedron, eight pieces of the imaging sections 15a to 15h cover all directions and therefore, one imaging section covers a field of view of 90 degrees in a horizontal plane, i. e., a field of view corresponding to one fourth of a hemisphere.

[0068] FIG. 9 illustrates a general configuration diagram of a fiber bundling unit 16a when employing the above-mentioned omnidirectional imaging unit 20 formed as a regular octahedron, and the fiber bundling unit 16a is formed such that cylindrical holes 17a, 17b . . . are arranged in two rows and two lines.

[0069] It should be noted that although the cylindrical holes formed in the fiber bundling unit 16a may be freely disposed depending on how the image fibers are bundled, disposing the image fibers in a lattice-like fashion facilitates the subsequent image processing to a larger extent.

[0070] Although the first embodiment constructed as described above has been described in which whole sky is divided at 30 degree intervals of latitude and longitude, the angular interval may arbitrarily be determined in the embodiment. When making a field of view for capturing images narrow as described above, the field of view of the imaging device becomes relatively near the telescopic-side field of view of a standard lens (around 50 mm) of a regular 35 mm camera, advantageously reducing distortions or the like of captured images. This is because the embodiment employs a plurality of image fibers and only utilizes images captured through a narrow field of view in front of each of the image fibers to substantially eliminate distortions of images captured by the individual image fibers.

[0071] Furthermore, since the imaging device of the embodiment includes all of the image fibers bundled together to obtain images through one image pickup device, the imaging device advantageously does not need operation for synchronizing images captured by a plurality of cameras, which operation is required when employing a plurality of cameras to capture images. In addition, the images on the image fibers, which are disposed horizontally, are disposed such that the images are captured by the same horizontal portion of the image pickup device. Accordingly, when cropping a portion of images on the image pickup device, reading data corresponding to necessary pixels arranged in horizontal and vertical directions based on location of the portion of images to be cropped makes it possible to blend a necessary range of images together. This means that operation for blending images together becomes very simple in comparison with that observed in the conventional device.

[0072] For this reason, when trying to blend together the images captured by a plurality of image fibers, the blending operation becomes very easy. This means that when cropping a portion of the captured omnidirectional images, the portion corresponding to an arbitrary direction and an arbitrary field of view, the following processing is performed simply, quickly and in an extremely advantageous manner.

[0073] Simplified processing makes compensation of distortions of individual images unnecessary and further, synchronization of a plurality of images unnecessary. Moreover, since positional relationship between images to be captured in longitudinal and lateral directions is maintained in longitudinal and lateral directions even on the image pickup device, even when cropping a rectangular portion of the captured images, complicated coordinate conversion is not required, thereby reducing the time necessary for processing.

[0074] Additionally, when disposing the image fibers 12a, 12b, 12c . . . corresponding to the imaging sections 15a, 15b, 15c . . . , which are disposed in a horizontal plane and on the same latitude on the side of the omnidirectional imaging unit, in a lattice-like fashion in the fiber bundling unit 16, the corresponding image fibers 12a, 12b, 12c . . . are disposed in the same horizontal line in the fiber bundling unit 16.

[0075] Subsequently, when the image pickup device captures the images in a situation where the spherical surface is developed such that the imaging sections on the same longitude are correspondingly disposed in the same longitudinal row in a plane, it becomes possible to view omnidirectional images like a global map. Accordingly, when cropping a portion of the developed omnidirectional images, the portion corresponding to an arbitrary direction and an arbitrary field of view, the cropping operation can be performed in an extremely simple manner since the portion to be cropped is easily identified based on positional relationship between the images.

[0076] As described above, the imaging device constructed in accordance with the first embodiment is able to easily capture omnidirectional images without distortions of images and even when monitoring the images to be captured, it is able to provide high visibility of omnidirectional images and in addition, perform associated processing in an extremely simplified manner even when cropping a portion of images.

[0077] Moreover, when employing an electronic equipment such as a computer with extraordinary ability to perform calculation and in addition, with extraordinary signal processing ability to perform conversion of coordinate in the imaging device, disposing the imaging sections in a practical pattern to promote more effective use of resolution associated with the image pickup device enhances flexibility of an entire imaging device. An omnidirectional imaging unit employing the above-described configuration and constructed in accordance with one embodiment will be explained with reference to FIG. 10.

[0078] FIGS. 10(a), 10(b) each illustrate a general configuration diagram of an omnidirectional imaging unit 20 formed as a regular icosahedron, and imaging sections 15a, 15b, 15c . . . , each being formed by bundling optical fiber cords together to form an equilateral triangle, are disposed in the center of the individual regular icosahedron planes.

[0079] In addition, regardless of spatial arrangement of the imaging sections 15a, 15b, 15c . . . , image pickup devices are disposed on the side of image pickup device so that resolution the image pickup device (CCD) has can effectively be utilized, as shown in FIG. 11. In this case, the imaging sections and/or lenses are preferably selected such that imaging field of view associated with the imaging device is able to cover space leaving no space between. The imaging device constructed as described above improves the usability of the image pickup device. Note that although the imaging section is configured to form an equilateral triangle when the omnidirectional imaging unit 20 is formed as a regular icosahedron, the imaging section configured to form a shape other than an equilateral triangle may produce the same effect as that could be obtained by employing the imaging section configured to form an equilateral triangle.

[0080] A second embodiment of the present invention will be explained with reference to FIGS. 12 through 16. In addition, the parts and components used in the second embodiment and also used in the first embodiment are denoted by the same numerals as those referred in the first embodiment, thereby omitting detailed explanation thereof.

[0081] FIGS. 12(a) to 12(c) generally illustrate a configuration diagram and enlarged views of the second embodiment of the present invention, and in FIGS. 12(a) to 12(c), imaging sections 15a, 15b, 15c . . . are constructed, as shown in FIG. 12(b), such that one ends of image fibers 12a, 12b, 12c . . . each are incorporated within a cylindrical member 14 and a light guide fiber 18 for emitting an illumination light for omnidirectional imaging utilizing a later described an illumination light source is formed on an outer periphery of the cylindrical member 14. The light guide fiber 18 is covered by an outer cylindrical member 19. Note that the other ends of the light guide fibers 18 are bundled together in the shape of a cylinder to form an illumination fiber bundling unit 30, as shown in the figure. Note that an objective lens is supported by the outer cylindrical member 19.

[0082] Moreover, to the illumination fiber bundling unit 30 shown in FIG. 13 is coupled an illumination light source unit 50 shown in FIG. 14. The illumination light source unit 50 is configured as shown in FIG. 15. As shown in FIG. 15, a light source lamp 52 and reflecting mirrors 53, 54 are disposed within a box member 51, and light rays from the light source lamp 52 are reflected by the reflecting mirrors 53, 54 to be inputted to the light guide fiber 18 of the illumination fiber bundling unit 30. The light rays inputted to the light guide fiber 18 are emitted from the distal ends of the imaging sections 15a, 15b, 15c . . . provided in the omnidirectional imaging unit 20 toward the surroundings.

[0083] As described above, since illumination light rays from the illumination light source unit 50 are emitted from the distal ends of the imaging sections toward the surroundings passing through the illumination fiber bundling unit 30 and the light guide fiber 18 in this order, shadow due to the orientation of the illumination light source is never produced and an entire illumination system can be reduced in volume to an extreme extent in comparison with the case where the illumination light source covers all directions.

[0084] FIG. 16 is a block configuration diagram of a circuitry for converting the images obtained by the imaging sections into an electrical signal using an image pickup device and processing the signal, and the electrical signal from the image pickup device 24 is processed in a signal processing unit 41 and the processed signal is recorded via a device interface unit 42 in a recording device 43 while being supplied to an external processing unit, not shown, via an external interface unit 44. Furthermore, the light guide fiber 18 for illumination is provided on the imaging section 15a and the illumination light source unit 50 for supplying light rays to the light guide fiber 18 is coupled to the light guide fiber 18.

[0085] FIGS. 17(a) to 17(c) generally illustrate a configuration diagram and enlarged views of a third embodiment of the present invention, and the parts and components used in the third embodiment and also used in the first and second embodiments are denoted by the same numerals as those referred in the first and second embodiments. In FIGS. 17(a) to 17(c), a number of optical fiber cords 11 are bundled together to constitute each of image fibers 12a, 12b, 12c . . . for capturing images through one ends of the image fibers. In addition, one ends of the image fibers 12a, 12b, 12c . . . constitute a plurality of imaging sections 15a, 15b, 15c . . .

[0086] As shown in FIG. 17(b), the imaging sections 15a, 15b, 15c . . . are constructed such that one ends of image fibers 12a, 12b, 12c . . . each are incorporated within a cylindrical member 14 and at the same time, a first light guide fiber 18a for emitting illumination light rays for omnidirectional imaging, which light rays are obtained from the illumination light source unit 50 shown in FIG. 15, and a second light guide fiber 18b for emitting strobe light rays from strobe illumination light source unit, not shown, are provided on an outer periphery of the cylindrical member 14 in a mixed form. The first and second light guide fibers 18a, 18b are covered by an outer cylindrical member 19.

[0087] It should be noted that the other ends of the first and second light guide fibers 18a, 18b each are bundled together in the shape of a cylinder to form first and second illumination fiber bundling units 30a, 30b, respectively, as shown in the figure.

[0088] FIG. 18 is a general configuration diagram illustrating an entire configuration employed in the third embodiment. To the first illumination fiber bundling unit 30a out of the first and second illumination fiber bundling units 30a, 30b shown in FIG. 18 is coupled the illumination light source unit 50 already described and shown in FIG. 14. In addition, although the above-mentioned light rays primarily consist of successively emitted light rays, strobe light rays from the strobe illumination light source unit, not shown, for periodically emitting light rays may be supplied to the second illumination fiber bundling unit 30b, and further, illumination by infrared rays other than strobe light rays may also be utilized in the imaging device.

[0089] As described above, the imaging device verifies its extremely high flexibility because it is able to address requirement for use in various applications such as by incorporating strobe light rays as illumination means in addition to regular visible light rays into the device. Furthermore, the imaging device may also be constructed such that during normal operation, infrared light rays are used for supervision or security and at the time of change of images to be displayed, strobe light rays are emitted.

[0090] As described above, since illumination light rays from the illumination light source unit 50 and the strobe illumination light source unit are emitted from the distal ends of the imaging sections to the surroundings through the first and second illumination fiber bundling units 30a, 30b and further, the first and second light guide fibers 18a, 18b, shadow due to the orientation of the illumination light source is never produced and an entire illumination system can be reduced in volume to an extreme extent in comparison with the case where the illumination light source covers all directions.

[0091] FIG. 20 is a block configuration diagram of a circuitry for converting the images obtained by the imaging sections into an electrical signal using an image pickup device and processing the signal. Components shown in FIG. 20 and different from those shown in FIG. 16 are first and second light guide fibers 18a, 18b and first and second illumination light source units 50a, 50b for supplying illumination light rays thereto.

[0092] As described so far, according to the present invention, the omnidirectional images captured by the imaging device indicate very small image distortions and at the same time, visibility of the images monitored by the imaging device increases to a large extent. In addition, shadow due to illumination rarely occurs, further enhancing visibility of the images at the time of simultaneous monitoring.

[0093] The images captured through the multiple point structure constructed by bundling a number of optical fiber cords together indicate small image distortions and further, have simple positional relationship therebetween to easily be detected, thereby allowing operation for cropping a portion of images corresponding to an arbitral field of view/direction to easily be performed. Furthermore, changing layout of the multiple point structure of the imaging sections makes it possible to flexibly address requirement for change of pattern or geometric range of the captured images.

[0094] Moreover, in addition to illumination by regular visible light rays, illumination by various light rays can be available by just changing a light source of an illumination light ray unit, whose light rays are supplied to an illumination light emitting unit, thereby easily meeting requirement for use to perform supervision/security and enhancing flexibility as a system to a large extent.

[0095] As described above, according to the present invention, the omnidirectional images captured by the imaging device indicate very small image distortions and at the same time, the images monitored by the imaging device provide very high visibility. In addition, shadow due to illumination rarely occurs, further enhancing visibility of the images at the time of simultaneous monitoring.

[0096] The images captured through the multiple point structure constructed by bundling a number of optical fiber cords indicate small image distortions and further, have simple positional relationship therebetween to easily be detected, thereby allowing operation for cropping a portion of image in an arbitral field of view and direction to easily be performed. Furthermore, changing layout of the multiple point structure of the imaging sections makes it possible to flexibly address requirement for change of pattern or geometric range of the captured images.