JP2004191593A - Imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus in which images are superposed even when a plurality of imaging parts are not focused and photography in a wide range is realized by the plurality of imaging parts. <P>SOLUTION: The imaging apparatus is provided with the plurality of imaging parts 10 equipped with an imaging means 1 and condensing means 3 and 4 condensing light so that the image may be formed on the imaging means 1. In each of the plurality of imaging parts 10, all the principal rays 2 passing between the condensing means 3 and 4 and the imaging means 1 are made nearly parallel with an optical axis 6, or the absolute value α of an angle formed by all the principal rays 2 with the optical axis 6 is set to 0<α<10°. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【００４０】
表１より、角度αが１０度未満であれば、ずれ量βは８ピクセル以内となる。
現状では、水平総画素数が７２０ピクセルの場合において、隣接する撮像部の画像をブレンドする（張り合わせて画像処理を行う）際に、隣り合う画像の色調やその他の要因で起こる微小なずれを目立たなくすることができるのは、この８ピクセル以内である。８ピクセルを越えるずれがあると、ブレンドしてもずれが残存し、違和感を生じさせることになる。
従って、角度の絶対値αは、α＜１０度であることが望ましいことがわかる。
【００４１】
なお、上述した具体的な形態の画角（水平方向３１度程度、垂直方向２３度程度）よりも画角が狭いレンズを使用して全方位を撮影する撮像装置を構成すると、撮像部（カメラ）の総数が７０個程度以上となるため、実用性が低くなる。
従って、各撮像部は上述した形態と同等の画角もしくはより大きい画角を有することが望ましい。
【００４２】
本発明は、上述の実施の形態に限定されるものではなく、本発明の要旨を逸脱しない範囲でその他様々な構成が取り得る。
【００４３】
【発明の効果】
上述の本発明によれば、各撮像部でフォーカスが合わされている被写体までの距離が異なっていても、像倍率をほぼ一致させることができるため、容易に隣り合う撮像部の画像を貼り合わせることができる。
これにより、各撮像部の設計条件をより自由に広く設定することができ、大きい撮像素子を用いて解像度を大きくしたり、撮像部の数を増やして画素数を増やしたりすることにより、画質を向上することが可能になる。また、撮像部毎に構成を異ならせたりすることも可能になる。
従って、本発明によれば、広い範囲の撮影を良好な画質で行うことが可能になる。
【００４４】
さらに、本発明によれば、画像を貼り合わせる際に要する時間を短縮することができる。
これにより、リアルタイムに処理を行うことができるため、生放送に適用することが可能になる。
また、撮像装置の構成を簡略化することが可能になる。
【図面の簡単な説明】
【図１】本発明の一実施の形態の撮像装置を構成する１つの撮像部の概略構成図である。
【図２】Ａ、Ｂ 図１の撮像部を多数配置して成る撮像装置の一形態の概略構成図である。
【図３】図１の撮像部を多数配置して成る撮像装置の他の形態の概略構成図である。
【図４】図１の撮像部において、ピントを合わせる被写体の距離を変化させたときの光路を示す図である。
Ａ 近距離の被写体にピントを合わせた場合である。
Ｂ 中距離の被写体にピントを合わせた場合である。
Ｃ 無限遠の被写体にピントを合わせた場合である。
【図５】従来の撮像装置の１つのカメラにおいて、ピントを合わせる被写体の距離を変化させたときの光路を示す図である。
Ａ 近距離の被写体にピントを合わせた場合である。
Ｂ 中距離の被写体にピントを合わせた場合である。
Ｃ 無限遠の被写体にピントを合わせた場合である。
【符号の説明】
１ 撮像手段、２ 主光線、３ 第１のレンズ群、４ 第２のレンズ群、５ 絞り、６ 光軸、１０ 撮像部（カメラ）、１１ 角錐ミラー[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an imaging apparatus including a plurality of imaging units each having a lens and an imaging element, and capable of capturing a wide range such as an entire circumference.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there have been proposed a number of imaging devices capable of simultaneously capturing a wide angle of view using a plurality of cameras.
[0003]
For example, an imaging device has been proposed in which the viewpoint centers of a plurality of cameras are virtually matched by using a pyramid mirror (for example, see Patent Document 1).
In such a configuration using a pyramid mirror, since the viewpoint centers of a plurality of cameras are optically coincident with each other, parallax does not occur between the cameras, and a plurality of images can be joined with high quality.
Further, even when a subject at a short distance from the camera is photographed, a blind spot where no photograph is taken does not occur.
[0004]
[Patent Document 1]
JP-B-39-8140 (FIG. 1)
[0005]
[Problems to be solved by the invention]
However, in the imaging apparatus having the above-described configuration, when one camera focuses on a short-distance subject and another adjacent camera focuses on a medium-distance subject, a long-distance subject is not focused on. Since the image magnification differs between the two cameras, the size of the image for a subject at a long distance differs.
[0006]
FIG. 5 shows an optical path of one camera in the imaging apparatus in which the viewpoint centers are made substantially coincident by using a plurality of cameras as described above.
FIG. 5A and FIG. 5B show optical paths in a case where a lens is moved to focus on a short-distance object, a medium-distance object, and a long-distance (infinity) object in one camera. , Shown in FIG. 5C.
[0007]
As shown in FIGS. 5A to 5C, the camera includes a first lens group 53 and a second lens group 54 as lenses, an aperture 55 disposed between the lens groups 53 and 54, and an imaging unit behind. As 51, for example, an image sensor (CCD solid-state image sensor or CMOS type solid-state image sensor) and a film are provided.
In this camera, as the first lens group 53 and the second lens 54, a commonly used lens, that is, a lens whose principal ray after passing through the lens is not parallel to the optical axis is used.
[0008]
Then, the distance between the lens groups 53 and 54 and the imaging unit 51 is changed in accordance with the distance to the subject, and more specifically, the relative position of the imaging unit 51 with respect to the lens groups 53 and 54 is moved. It is configured to form an in-focus image on 51.
[0009]
Regarding the size of the image with respect to the angle of view (not shown) of the lenses 53 and 54, that is, the size of the image corresponding to both ends of the imaging area, the distance of the focused object is short ( It is constant at Y0 in any case of the middle distance (FIG. 5B) and the infinity (FIG. 5C).
[0010]
On the other hand, the image of the subject located at infinity is the same position as the image when focusing on infinity shown in FIG. 5C, that is, the position of the distance LF from the aperture 55, and the distance of the focused subject is Is constant regardless of
Then, as shown in FIG. 5A, when focusing on a subject at a short distance, the size of the image of the subject located at infinity is Y1. At this time, since the chief ray 52 spreads after passing through the lenses 53 and 54, Y1 <Y0.
Similarly, as shown in FIG. 5B, when a subject at a middle distance is focused, the size of the image of the subject located at infinity is Y2. Also at this time, the principal ray 52 spreads after passing through the lenses 53 and 54, so that Y2 <Y0. In addition, since the degree of spread of the principal ray 52 after passing through the lenses 53 and 54 is larger than when focusing on an object at a short distance, Y1 <Y2 <Y0.
[0011]
Therefore, when one camera focuses on a short-distance subject and another adjacent camera focuses on a medium-distance subject, the size of an image of a distant subject such as a background (that is, (Magnification) is different.
[0012]
If the image magnifications differ greatly between adjacent cameras, it becomes difficult to combine images from these adjacent cameras.
In other words, if an attempt is made to adjust the images of adjacent cameras by scaling the images so that images at short distances are continuous, the background images will not be continuous. On the other hand, if an attempt is made to enlarge and reduce the image so that images at long distances are continuous, the images at short distances will not be continuous.
[0013]
As a method for solving this problem, for example, a method in which short-range, medium-range, and long-range images are each converted into an object for each distance, the image is scaled for each objectized image, and the image is superimposed again is considered. Can be
However, in this method, it is difficult to cope with a case where the subject is continuous from a short distance to a long distance, and it takes a long processing time.
[0014]
When the size of the image sensor is small and a wide-angle lens is used, the depth of field is widened, so that this problem is hard to become obvious.
On the other hand, there is a problem when a narrow-angle lens (telephoto lens or the like) is used or when a large image sensor is used.
Therefore, it is necessary to align the focus with all cameras at the time of photographing, which has been a great limitation.
[0015]
In order to solve the above-described problem, according to the present invention, an imaging apparatus capable of superimposing images without focusing on a plurality of imaging units and performing wide-range imaging with the plurality of imaging units Is provided.
[0016]
[Means for Solving the Problems]
An imaging apparatus according to the present invention includes a plurality of imaging units each including an imaging unit and a light collection unit that collects light to form an image on the imaging unit. All principal rays passing between the optical means and the imaging means are substantially parallel to the optical axis.
The principal ray is defined as a ray passing through the center of the aperture stop except for the optical axis.
[0017]
An imaging apparatus according to the present invention includes a plurality of imaging units each including an imaging unit and a light collection unit that collects light to form an image on the imaging unit. Assuming that the absolute value of the angle between all the principal rays passing between the optical means and the imaging means and the optical axis is α, 0 <α <10 degrees.
[0018]
According to the configuration of the imaging apparatus of the present invention described above, in each imaging unit of the plurality of imaging units, any principal ray passing between the light collecting unit and the imaging unit is substantially parallel to the optical axis, or By setting the absolute value α of the angle between the optical axis of the principal ray and the optical axis to be 0 <α <10 degrees, it is possible to make the image magnifications substantially the same or to make the difference between the image magnifications extremely small in a plurality of imaging units. become.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
As one embodiment of the present invention, FIG. 1 shows a schematic configuration diagram of one imaging unit (camera) constituting an imaging device.
Then, by arranging a large number of imaging units (cameras) 10 shown in FIG. 1 as described later, an imaging device that captures a wide range is configured.
[0020]
As shown in FIG. 1, each imaging unit 10 includes a front first lens group 3 and a rear second lens group 4, a diaphragm 5 disposed between these lens groups 3 and 4, The imaging unit 1 includes, for example, an imaging device (CCD solid-state imaging device or CMOS solid-state imaging device) and a film. These components 1, 3, 4, and 5 are arranged along the optical axis 6 shown in the figure.
[0021]
Then, by changing the distance between the lens groups 3 and 4 and the image pickup means 1 in accordance with the distance to the subject, specifically, by moving the relative position of the image pickup means 1 with respect to the lens groups 3 and 4, It is configured to form an in-focus image on the means 1.
[0022]
As a configuration of an imaging device in which many imaging units (cameras) 10 are arranged, for example, as shown in a plan view of FIG. 2A and a cross-sectional view taken along a line AA of FIG. A configuration in which the viewpoint centers 20 of the imaging units 10 are virtually substantially coincident with each other, or a plurality of imaging units 10 are radially arranged without using a mirror so that the viewpoint centers 20 coincide with each other, for example, as shown in FIG. Configurations are possible.
In any of the configurations of the imaging devices, the effects of the present invention described later can be obtained.
[0023]
The lenses 3 and 4 and the imaging unit 1 used for each imaging unit (camera) 10 may have a different configuration for each imaging unit 10 as described later, but the same configuration is commonly used for all the imaging units 10. Can be used.
[0024]
In the imaging apparatus according to the present embodiment, in particular, in each imaging unit (camera) 10, for any principal ray 2 (see FIG. 4) passing between lens groups 3 and 4 and imaging means 1, When the absolute value of the angle is α, α is almost 0, that is, all principal rays 2 passing between the lens groups 3 and 4 and the imaging unit 1 are substantially parallel to the optical axis 6.
The principal ray 2 is defined as a ray passing through the center of the aperture stop 5 except for the optical axis 6, which is defined as the F number is sequentially increased, that is, the aperture is increased with the same lens aperture. It corresponds to the light beam excluding the optical axis 6 among the light beams that reach the imaging means 1 when moving.
[0025]
Next, FIG. 4 shows an optical path of one imaging unit (camera) 10 in the imaging apparatus according to the present embodiment.
In FIG. 4, the optical paths in the case where the lens is moved in one imaging unit 10 to focus on a short-distance object, a medium-distance object, and a long-distance (infinity) object are respectively shown in FIG. 4A. , FIG. 4B and FIG. 4C.
In FIG. 4, since the optical path is shown for one cross section of the imaging unit 10, only two chief rays 2 are shown. Ray 2 is present.
[0026]
The size of the image with respect to the angle of view (not shown) of the lenses 3 and 4, that is, the size of the image corresponding to both ends of the imaging region, is the same as in the conventional camera shown in FIG. Y0 is constant regardless of whether the distance of the focused object is short (FIG. 4A), medium (FIG. 4B), or infinity (FIG. 4C).
This is because the angle of view and the focal length f of the lenses 3 and 4 are constant regardless of the focus state.
[0027]
The image of the subject located at infinity is the same position as the image when focusing on infinity shown in FIG. 4C, that is, the position of the distance LF from the aperture 5, and the distance of the focused subject is Is constant regardless of
Then, as shown in FIG. 4A, when focusing on a subject at a short distance, the size of the image of the subject located at infinity is Y3. At this time, since the principal ray 2 is substantially parallel to the optical axis 6, Y3 = Y0.
Similarly, as shown in FIG. 4B, when a subject at a middle distance is focused, the size of the image of the subject located at infinity is Y4. Also at this time, since the principal ray 2 is substantially parallel to the optical axis 6, Y4 = Y0.
That is, Y3 = Y4 = Y0.
[0028]
This means that even when one imaging unit (camera) focuses on a short-distance object and another adjacent imaging unit (camera) focuses on a medium-distance object, these adjacent imaging units may be focused. Means that the size (image magnification) of an image of a subject at a long distance such as the background is the same in each image.
Since the image magnifications are the same, no problem occurs when the images of the adjacent imaging units are pasted together.
[0029]
At this time, since the distance between the objects to be focused by the adjacent imaging units 10 is different, the degree of occurrence of blur due to the defocus of the image is different. , The degree of blur can be adjusted to the same extent so that there is no sense of incongruity at the joint of the images.
In this case, the image processing can be performed in a short time because relatively simple processing is sufficient.
[0030]
Heretofore, it has been necessary for a plurality of cameras to perform shooting at the same subject distance.
On the other hand, according to the configuration of the present embodiment, it is possible to easily superimpose images by image processing even if the object distance of focus is different, so that the focus of all the imaging units is set to the same object distance. There is no need to
[0031]
This makes it possible to more freely set the design conditions of each imaging unit 10, for example, to increase the resolution by using a large imaging device for the imaging unit, or to set the imaging unit (camera) 10 that constitutes an imaging device, for example. Can be increased to increase the number of pixels, or, for example, the configuration of components and the like can be changed for each imaging unit (camera) 10.
When the resolution is increased or the number of pixels is increased, the depth of field of the lenses 3 and 4 becomes narrower, so that it is necessary to precisely focus in each imaging unit 10. According to the above, since the position for focusing with another imaging unit 10 does not need to be matched, the focusing position in each imaging unit 10 can be changed according to the distance to the subject.
Therefore, it is possible to easily improve the image quality by increasing the resolution or increasing the number of pixels.
[0032]
According to the above-described embodiment, in each of the imaging units 10 constituting the imaging apparatus, the chief ray 2 that has passed through the second lens group 4 is configured to be substantially parallel to the optical axis 6, so that imaging is performed. Even if the focused position is different for each unit 10, the image magnifications are substantially the same, so that the images of the adjacent imaging units 10 can be easily pasted together.
In addition, since the image magnifications are substantially the same even if the focused focus position is different for each imaging unit 10, the design conditions of each imaging unit 10 can be set more freely, and a large imaging element can be used. It is also possible to increase the number of pixels by increasing the number of imaging units 10, or to make the configuration different for each imaging unit 10.
[0033]
In particular, when a large imaging element is used or the number of imaging units 10 is increased to narrow the angle of view of the lens of each imaging unit, the depth of field becomes narrow. You need to adjust to different focus positions. Even in such a case, since the image magnifications are substantially the same, it is possible to smoothly connect adjacent images without making the focus positions coincide in each imaging unit.
Therefore, it is possible to easily improve the image quality by increasing the resolution by using a large image sensor or increasing the number of pixels by increasing the number of the image pickup units 10.
[0034]
In addition, since the image processing at the time of pasting the images becomes unnecessary or can be simplified, the time required at the time of pasting the images can be shortened, so that the processing can be performed in real time. Can be applied to live broadcasting.
[0035]
In the above-described embodiment, the case where the present invention is applied to an imaging device that captures an image of an entire circumference of a cylinder is described. However, for example, an imaging device that performs panoramic imaging of a partial area that does not cover all directions, The present invention can also be applied to an imaging device that captures a spherical omnidirectional image having a direction as an imaging region.
[0036]
Further, in the above-described embodiment, all the principal rays 2 located between the light condensing units 3 and 4 and the imaging unit 1 are substantially parallel to the optical axis 6, and the angle formed by all these principal rays 2 with the optical axis 6. Is set to substantially zero, but the effect of the present invention can be obtained if the absolute value α of this angle is in a sufficiently small range.
[0037]
Then, in order to easily perform image processing at the time of bonding the images of the respective imaging units 10, it is desirable that the absolute value α of the angle formed by the principal axis 2 with the optical axis 6 satisfies α <10 degrees. When α = 0, the principal ray 2 becomes parallel to the optical axis 6.
For example, the absolute value α of this angle can be set to 9 degrees.
[0038]
Here, the value of the absolute value α of the angle was changed and the change in the deviation β of the size of the image of the subject was examined.
A camera having a horizontal angle of view of 31 degrees and a vertical angle of view (vertical direction) of 23 degrees is used. As an image sensor, one side in the horizontal direction is 8.8 mm, and one side in the vertical direction is 4.4 mm. One imaging unit 10 of the imaging apparatus was configured using a CCD imaging device having 720 pixels in the direction and 480 pixels in the vertical direction.
Then, a deviation β [pixel] of the size of the image of the subject located at a short distance of 0.5 m with respect to the image of the subject located at infinity was obtained by changing the magnitude of the angle α [degree]. . Table 1 shows the results. The deviation β of the size of the image of the subject is a value obtained by converting the deviation amount of the size of the image in pixel units, and thus has a numerical value below the decimal point.
[0039]
[Table 1]

[0040]
According to Table 1, when the angle α is less than 10 degrees, the shift amount β is within 8 pixels.
At present, when the total number of horizontal pixels is 720 pixels, a minute shift caused by the color tone of adjacent images or other factors is noticeable when blending images (adhering and performing image processing) of the adjacent imaging units. Only eight pixels can be eliminated. If there is a shift exceeding 8 pixels, the shift will remain even after blending, causing a sense of incongruity.
Therefore, it is understood that the absolute value α of the angle is desirably α <10 degrees.
[0041]
Note that if an imaging apparatus that captures images in all directions using a lens whose angle of view is narrower than the angle of view (about 31 degrees in the horizontal direction and about 23 degrees in the vertical direction) in the specific form described above, an imaging unit (camera) ) Is about 70 or more, so that the practicality is low.
Therefore, it is desirable that each imaging unit has an angle of view equal to or larger than that of the above-described embodiment.
[0042]
The present invention is not limited to the above-described embodiment, and may take various other configurations without departing from the gist of the present invention.
[0043]
【The invention's effect】
According to the above-described present invention, even if the distance to the focused object is different in each imaging unit, the image magnifications can be substantially matched, so that the images of the adjacent imaging units can be easily pasted together. Can be.
As a result, the design conditions of each imaging unit can be set more freely and broadly, and the image quality can be increased by increasing the resolution by using a large imaging element or by increasing the number of pixels by increasing the number of imaging units. Can be improved. Further, it is also possible to make the configuration different for each imaging unit.
Therefore, according to the present invention, it is possible to shoot a wide range with good image quality.
[0044]
Further, according to the present invention, it is possible to reduce the time required for bonding images.
Thereby, since the processing can be performed in real time, it can be applied to live broadcasting.
Further, the configuration of the imaging device can be simplified.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of one imaging unit included in an imaging device according to an embodiment of the present invention.
FIGS. 2A and 2B are schematic configuration diagrams of one embodiment of an imaging apparatus in which a number of imaging units in FIG. 1 are arranged.
FIG. 3 is a schematic configuration diagram of another embodiment of an imaging device in which a number of imaging units in FIG. 1 are arranged.
FIG. 4 is a diagram illustrating an optical path when the distance of a subject to be focused is changed in the imaging unit in FIG. 1;
A: This is a case where a subject at a short distance is focused.
B This is a case where a subject at a medium distance is focused.
C is a case in which a subject at infinity is focused.
FIG. 5 is a diagram illustrating an optical path when a distance of a subject to be focused is changed in one camera of a conventional imaging apparatus.
A: This is a case where a subject at a short distance is focused.
B This is a case where a subject at a medium distance is focused.
C is a case in which a subject at infinity is focused.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 imaging means, 2 principal rays, 3 first lens group, 4 second lens group, 5 stop, 6 optical axis, 10 imaging unit (camera), 11 pyramid mirror

Claims (2)

An image pickup unit, comprising a plurality of image pickup units provided with light condensing means for condensing light and forming an image on the image pickup means,
In each imaging unit of the plurality of imaging units, any principal ray passing between the condensing unit and the imaging unit is substantially parallel to the optical axis. An image pickup unit, comprising a plurality of image pickup units provided with light condensing means for condensing light and forming an image on the image pickup means,
In each of the imaging units of the plurality of imaging units, when the absolute value of the angle formed by the principal axis passing between the condensing unit and the imaging unit and the optical axis is α,
An imaging apparatus, wherein 0 <α <10 degrees.

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