JP2002314867A - Imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit the generation of parallax between images that are picked up by a plurality of cameras. SOLUTION: In the image pickup apparatus, a wide range of subject is divided and each of the divided subjects is picked up by video cameras 21 and 25 individually for laminating into one image by a processing means for inputting image information from each video camera. A group of lenses 22, 23, 26, and 27 comprising lenses are provided in each lens barrel of each video camera, a straight constituent at the object space of main rays located at a Gauss region through the center of the opening diaphragm of a lens is extended, a point that crosses the light axis P1 is set to a first NP point Q, and another, second NP point Q2 is arranged at a region with a radius of 20 mm with the first NP point Q as a center.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention reduces parallax, which is the parallax between images, when, for example, an image of a subject in a wide semispherical space is picked up by a plurality of cameras and each image is pasted together. The present invention relates to an imaging device capable of performing the operation.

[0002]

2. Description of the Related Art As is well known, a plurality of video cameras are connected to one video camera.
Various cameras have been developed which can be housed in a single box to simultaneously capture images in all directions or all positions.

[0003] In order to obtain a wide-range image such as a panoramic image by photographing the surroundings on a horizontal plane from a point in space as a viewpoint, for example, as shown in FIG. Are arranged at equal intervals in the circumferential direction, and the optical axes 3, 4 of the lenses 1a, 2a of the cameras 1, 2,... Are fixed in the radial direction. , 2,... Enables the entire circumference to be photographed by connecting the overlapping portions of the individual images photographed. In the figure, reference numerals 5 and 6 denote imaging elements such as CCDs provided at the rear end of each lens.

[0004]

By the way, when the images taken by the plurality of cameras 1 and 2 are connected to each other as described above, an overlapped portion or a case where no overlap is provided. However, so-called parallax is likely to occur at a place where images are joined, and how to reduce the parallax is a technical problem in such an imaging processing technique.

However, in the conventional imaging apparatus, the arrangement of the cameras 1, 2,... Is simply set at a position where each part of the subject is imaged. There are not enough ideas to be resolved.

[0006] As a result, the parallax causes a serious obstacle when bonding the overlapped portions of the images after the photographing is completed, and the connection of the images is lost.

[0007]

SUMMARY OF THE INVENTION The present invention has been devised in view of the actual condition of the conventional apparatus, and the invention according to claim 1 divides a wide range of objects into a plurality of divided objects. An image pickup apparatus that individually shoots a plurality of units by a plurality of image pickup units, and performs a bonding process on one image by a processing unit that inputs image information from each of the image pickup units. Among the chief rays passing through the center of the aperture stop, a chief ray located in the Gaussian region is selected, a straight line component in the object space of the selected chief ray is extended, and a point intersecting with the optical axis is set as an NP point, Each NP of each of the imaging means
The points are grouped in a predetermined radius area centered on one NP point.

The principle of the present invention will be briefly described with reference to FIG. 1 which is a schematic diagram. Lenses used in video cameras and the like are designed so that aberrations such as chromatic aberration, field curvature, and flare are minimized by combining a plurality of lenses. Such a lens is composed of one thin convex lens 11 as shown in FIG. 1 in principle.
At the focal position of the convex lens 11, a video imaging device such as a CCD or a MOS or an imaging device 12 which is a film in the case of a silver halide camera is arranged.

In the image pickup apparatus having such a basic structure, the angle of view α is substantially equal to the diameter d1 of the image pickup element 12 and the distance d4 between the convex lens 11 and the image pickup element 12, when the refraction by the convex lens 11 is ignored. (Focal length), and can be expressed by the formula of tan (α / 2) = (d1 / 2) / (d4).

Therefore, when an object is photographed by using such a camera, if the image is taken while rotating around an NP point (non-parallax point) 13 described later, which is located at the center of the inside of the convex lens 11, the image can be obtained. Parallax does not occur between a plurality of images.

Here, the NP point refers to how the inventor of the present invention can reduce parallax generated when a plurality of images are connected based on a basic idea of an optical system. This is detected as a result of many experiments and is described in the case where the light reflected by the object forms an image on the imaging unit 301 via the equivalent convex lens 300 as shown in FIG.

That is, the equivalent convex lens 300 is constituted by a plurality of lenses 302 to 308, and the aperture stop 30
9 is provided between the lens 304 and the lens 305. Then, of the innumerable principal rays passing through the center of the aperture stop 309, a principal ray 311 passing through a region closest to the optical axis 310, that is, a Gaussian region having the smallest aberration is selected.
A point at which a straight line component in the object space 312 of the principal ray 311 is extended to intersect with the optical axis 310 is set as an NP point (non-parallax point) 313.

Then, after verifying the existence of the NP point 313, the present invention is applied to a case where a plurality of cameras are used. Instead of rotating one camera, an image is picked up using a plurality of cameras at the same time. In this case, the position of the NP point 13 is limited to only the restricted point in one convex lens 11 shown in FIG.
Although it is physically impossible to arrange the P point 13 in common, the NP point 313 is formed by combining a plurality of lenses like the equivalent convex lens 300 shown in FIG.
Can be set almost anywhere on the extension of the optical axis 310.

Therefore, the present invention is such that the NP points 313 of all other cameras are located within a predetermined radius area (spherical area) centered on the NP point 313 of any one camera. is there. Thus, when capturing images using a plurality of cameras, the viewpoints of the cameras can be shared, so that parallax does not occur between camera images.

The invention according to claim 2 is characterized in that the predetermined radius region is set to about 20 mm centering on one NP point.

When the radius area is larger than 20 mm, parallax becomes particularly large when capturing an object close to the camera, and when connecting adjacent images,
Smooth connections are often lost.

According to a third aspect of the present invention, a plurality of lenses of the image pickup means are provided in multiple stages, and a lens group including the plurality of lenses is provided in a lens barrel.
A plurality of lens barrels are collectively arranged on one support.

[0018]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of an image pickup apparatus according to the present invention.

FIG. 3 shows a first embodiment of an image pickup apparatus according to the present invention, in which two video cameras as image pickup means are provided.
A front lens group 22 provided at a front position of a lens barrel, and a lens group 23 including a plurality of lenses 23a to 23f at a rear position.
And a CCD 24 which is an imaging device provided at the rearmost position.
And On the other hand, the second video camera 25 also has a front lens 26 also provided at a front position of the lens barrel, a lens group 27 including a plurality of lenses 27a to 27f at a rear position, and an imaging device provided at a rearmost position. CCD as an element
28.

Each of the front lenses 22, 26 is constituted by a concave lens, and each of the lenses 23a to 23f, 27a to 27f of each of the lens groups 23, 27 is constituted by a combination of concave and convex lenses.

The CCDs 24 and 28 have a flat plate shape.
Optical axis P of each lens and lens groups 22, 23, 26, 27
1, P2, and fixed to the rear end of the lens barrel.

The first video camera 21 has an aperture stop 29 provided between the lens 23b and the lens group 23c. Then, of the innumerable principal rays passing through the center of the aperture stop 29, a principal ray passing through a region closest to the optical axis P1, that is, a Gaussian region having the smallest aberration is selected. A point at which a straight line component in the object space of the principal ray intersects with the optical axis P1 is defined as a first NP point (non-parallax point).
It is set as Q.

In the second video camera 25, an aperture stop 30 is provided between the lens 27b and the lens 27c. Then, of the innumerable principal rays passing through the center of the aperture stop 30, the area closest to the optical axis P2, that is, the principal ray passing through the Gaussian area is selected. A point at which the straight line component in the object space of the principal ray intersects with the optical axis P2 is defined as a second point.
Is set as the NP point Q2.

The second NP point Q2 is set so as to be located in a region (spherical region) having a radius of 20 mm around the first NP point Q.

Here, α and β in FIG. 3 are the imaging angles of view of the lenses of the respective video cameras 21 and 22, and the hatched portion 31 is the overlap area of the images from the video cameras 21 and 25.

Therefore, according to this embodiment, the image of the subject incident into each lens barrel is divided into a plurality of lens groups 22, 23, 2 within the angles of view α and β as shown in FIG.
After passing through 6, 27, they are input to the CCDs 24, 28. After that, the image is output to the processing unit while being processed by the processing unit. Here, the plurality of images are laminated while overlapping the overlap unit 31.

The respective lenses 22, 23a to 23f, 25, 26, 27a to
The incident light passing through 27f forms NP points Q and Q2 in the above-described predetermined area at a substantially central position of the lens barrel. Accordingly, the occurrence of the parallax phenomenon by the plurality of video cameras 21 and 25 is prevented, the images are stuck together, and highly accurate image processing can be performed.

FIG. 4 shows a second embodiment of the present invention, in which a lens barrel hole formed at an opening angle position of about 56 degrees is provided at a front end of a housing 40 having a substantially circular cross section. Has two lens barrels 41 and 42 inserted and fixed,
A plurality of lenses 43, 4 are provided in each of the lens barrels 41, 42.
4 are provided.

At the rear end of the housing 40, element lens barrels 45 and 46 are inserted and fixed in lens barrel holes formed on the optical axes P1 and P2 of the lenses 43 and 44, respectively. CCDs 47 and 48 as image pickup devices are fixed to the inner rear ends of the element barrels 45 and 46, respectively.
Processing units and processing means (not shown) are electrically connected to 47 and 48.

Also in this embodiment, the NP points Q and Q1 corresponding to the respective lenses are set in the housing 40 by combining a plurality of lenses 43 and 44, respectively.

Therefore, the occurrence of the parallax phenomenon by a plurality of video cameras is prevented, the images are stuck well, and high-precision image processing can be performed.

Further, since a plurality of cameras can be provided in one housing 40, the whole apparatus can be made compact.

FIG. 5 shows a third embodiment, in which a gap is provided between a plurality of lens groups 51 and 52 of a video camera.
Each lens 51a, 51b, 51c of the front lens group 51,
Arrangement of 51d and each lens 52a, 5 of rear lens group 52
2b by arbitrarily changing the arrangement of NP
Point Q was set at a position behind lens group 52 as shown. In the figure, 53 is a CCD.

Therefore, if the NP points of the other video cameras are set in accordance with the NP point Q set at the rear position of the lens group 52, they can be set as a common NP point.

By changing the positions of these NP points Q arbitrarily, a common NP point Q for a plurality of video cameras can be obtained. As a result, a wide-angle camera without parallax can be designed.

FIG. 6 shows a fourth embodiment of the present invention. In this embodiment, the entire circumference can be photographed using four cameras arranged at an angular position of about 90 degrees in the circumferential direction. The lens groups 75 to 78 provided in the lens barrels 71 to 74 of the cameras respectively include a plurality of lenses 75a,
75b, 76a, 76b, 77a, 77b, 78a, 7
8b, and these optical axes P1 to P4 are set so as to be in the tangent direction at the 90-degree position of the virtual circle O at the center.

Then, as shown in the figure, the NP points Q1, Q2, Q3,
Q4 was set at a position close to each other at a position of 90 degrees in the circumferential direction of the virtual circle O.

Therefore, according to this embodiment, each N
Since the P points Q1, Q2, Q3, and Q4 are not at a common position but are slightly shifted from each other, parallax occurs between the video cameras.
Since the deviation between Q2, Q3 and Q4 is small, parallax can be made sufficiently small.

In addition, the entire periphery of the subject can be photographed by the unique arrangement of the cameras, and the degree of freedom of the arrangement is improved. Further, the entire device can be made compact.

It is also possible to arrange a plurality of cameras not only two-dimensionally but also three-dimensionally in the vertical direction.

The present invention is not limited to the configuration of each of the embodiments described above, and it is possible to perform three-dimensional and efficient shooting by increasing or decreasing the arrangement and number of video cameras.

[0042]

As is apparent from the above description, according to the first aspect of the present invention, the NP points of the plurality of image pickup means are set as follows.
Since it can be arranged at a substantially common position within a predetermined area range, the occurrence of parallax can be effectively suppressed. As a result, highly accurate image processing can be performed.

According to the second aspect of the present invention, since the predetermined area range is set within a spherical area having a radius of 20 mm centering on one NP point, the collectivity of each NP point is improved, and parallax is improved. Can be further suppressed.

According to the third aspect of the present invention, since a plurality of image pickup means are collectively arranged on one support, the degree of freedom of the structure of the apparatus is improved, and the entire apparatus can be made compact.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of an imaging apparatus according to the present invention.

FIG. 2 is a diagram illustrating the principle of an imaging apparatus according to the present invention.

FIG. 3 is a plan view showing the first embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a second embodiment of the present invention.

FIG. 5 is a transverse sectional view showing a third embodiment of the present invention.

FIG. 6 is a schematic view showing a fourth embodiment of the present invention.

FIG. 7 is a schematic plan view showing a conventional imaging device.

[Explanation of symbols]

 21 · 25 video camera 22, 23, 26, 27 lens group 24, 28 CCD 40 support 41 · 42 lens barrel 43, 44 lens

Continued on the front page F-term (reference) 5C022 AC51 AC54 AC77

Claims (3)

[Claims] 1. A wide-range subject is divided and each of a plurality of divided subject portions is individually photographed by a plurality of image pickup means, and the image information from each of the image pickup means is input into a single image by a processing means. An imaging device for performing a matching process, wherein a chief ray located in a Gaussian region is selected from chief rays passing through the center of an aperture stop of a lens provided in the imaging means, and a straight line in the object space of the selected chief ray is provided. A point at which the component intersects with the optical axis is set as an NP point, and each NP point of each of the imaging means is gathered in a predetermined radius area centered on one NP point. Imaging device. 2. The imaging apparatus according to claim 1, wherein the predetermined radius area is set to about 20 mm centering on one NP point. 3. A plurality of lenses of the image pickup means are provided in a multistage manner, a lens group including the plurality of lenses is provided in a lens barrel, and the plurality of lens barrels are collectively arranged on one support. The imaging device according to claim 1 or 2, wherein