JP2002271661A - Imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make an imaging device more coup comprising a combination of a convex mirror and a camera by decreasing number of components coup at in size. SOLUTION: A convex mirror 1 is fitted directly to an objective lens 12a which is a component of a CCD camera 12 by using an adhesive or screws, so as to eliminate the need for a transparent cylinder and also a light shade rod having been required for conventional imaging devices, thereby decreasing the number of components and waking the imaging device coup at in size.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus, and has a simplified structure of an image pickup apparatus for photographing a hemisphere.

[0002]

2. Description of the Related Art An image pickup apparatus as shown in FIG. 7 has been proposed for obtaining a wide-range image in a semi-celestial sphere (Japanese Patent Laid-Open No. 11-174603).

In the figure, reference numeral 2 denotes a camera, 6 denotes a ring plate having a window hole 7 corresponding to the objective lens of the camera 2, 3 denotes a transparent cylinder,
Reference numeral 5 denotes a support plate that closes the upper end of the transparent tube 3, 1 denotes a convex mirror having a rotationally symmetric shape, 4 denotes a light shield that prevents light reflected on the inner peripheral surface of the transparent tube 3 from entering the camera 2 via the convex mirror 1. It is a rod.

In such an image pickup apparatus, since the light traveling toward the convex mirror 1 is reflected by the convex mirror 1 and converges on the objective lens of the camera 2, a wide-range image of the space of the hemisphere below the position of the support plate 5 (by the camera 2) Except for the blind spot). On the other hand, in FIG. 8, unlike the light a that goes directly to the convex mirror 1 from the outside, the light b that is reflected by the inner peripheral surface of the transparent cylinder 3 and goes to the convex mirror 1 is blocked by the presence of the light shielding rod 4. The light b reflected on the inner peripheral surface of the transparent cylinder 3 does not enter the camera 2.

[0005]

However, such an imaging apparatus has a problem that not only the number of components is large but also the dimension in the axial direction is large.

Accordingly, an object of the present invention is to provide an image pickup apparatus which solves the above problem.

[0007]

According to a first aspect of the present invention, there is provided an image pickup apparatus comprising: a convex mirror; and an imaging unit disposed to face the convex mirror and located on the front side of the convex mirror. In an imaging apparatus provided with a first imaging unit including a first objective lens and an imaging unit for taking an image, wherein the convex mirror and the first objective lens are fixed,
According to a second aspect of the present invention, in the imaging device according to the first aspect,
A screw member is used for the fixing, and the configuration of the imaging apparatus according to claim 3 is characterized in that, in claim 1, the adhesive is used for the fixing, and the imaging apparatus according to claim 4 is used. The configuration of the apparatus according to claim 3, wherein a second objective lens for photographing an object to be photographed on the rear side of the convex mirror is provided on the rear side of the convex mirror, and light from the second objective lens is substantially centered on the imaging unit. 6. An image pickup device according to claim 5, wherein an optical path for guiding the light to the convex mirror is formed in the convex mirror as a second image pickup means, and images from the respective image pickup sections are pasted to obtain a wide range image. According to a fourth aspect of the present invention, in the configuration of the imaging apparatus according to the sixth aspect, the imaging unit uses an image sensor in the fifth aspect. Are set to overlap with each other According to a seventh aspect of the present invention, in the configuration of the sixth aspect, among the principal rays passing through the centers of the apertures provided in the first and second imaging units, the principal rays passing through the Gaussian region are changed. A point which intersects with the optical axis by extending a linear component of the principal ray in the object space is set as an NP point, and the inside of a sphere centered on the NP point is set as an NP point area, The NP point of any one of the means and the second imaging means is set so as to be arranged in the other NP point area, and the configuration of the imaging apparatus according to claim 8 is the same as that of claim 7, , Wherein the radius dimension of the NP point region is approximately 20 mm.

The NP point and the NP point area are defined below. FIG. 6 shows a state in which light reflected by a subject (not shown) reaches the imaging unit 301 via the equivalent convex lens 300 and forms an image on the imaging unit 301. The equivalent convex lens 300 includes lenses 302 to 308
And an aperture 309 is provided between the lens 304 and the lens 305. Among the innumerable chief rays passing through the center of the stop 309, a chief ray 311 whose lens aberration is negligible is selected through a Gaussian region near the optical axis 310, and a straight line in the object space 312 among the selected chief rays 311 is selected. A point where the component is extended and intersects with the optical axis 310 is defined as an NP (non-parallax) point 313, and the inside of a sphere having a radius of 20 mm or less centered on the NP point is defined as an NP point area 314. The reason why the NP point area is set in the sphere having a radius of 20 mm centered on the NP point is that the NP point area of any one of the imaging units is set within the sphere having a radius of 20 mm centered on the NP point.
This is because if the NP points are close to each other where the points are located, the occurrence of parallax can be suppressed to a negligible level. 315 is an image space.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an imaging apparatus according to the present invention will be described.

(A) First Embodiment First, a first embodiment will be described. As shown in FIG. 1, a CCD camera 12 is used in this embodiment as a camera. The CCD camera 12 is provided with an objective lens 12a. Note that the camera may be a still camera.

The convex mirror 1 is fixed to the objective lens 12a without passing through a transparent tube. The reason for the direct fixing is as follows. Transparent cylinder 3 as shown in FIG.
Even if the lens is interposed, the lower part of the CCD camera 12 cannot be photographed due to the presence of the CCD camera 12 and an imageless portion is generated at the center of the image. If the convex mirror 1 and the objective lens 12a are directly fixed, the objective lens 12a Is closer to the convex mirror 1, the area of the non-image portion is slightly increased, but there is no great difference in performance.

Since the contact area between the convex mirror 1 and the objective lens 12a is small, the fixing strength is likely to be low. Therefore, as a fixing means, an adhesive 10 may be used as shown in FIG. ), A resin screw (screw member) 11 inserted into the through hole 1a of the convex mirror 1 may be screwed into the female screw portion 12f of the objective lens 12a. FIG. 2 (c)
The screw 12d is formed integrally with the objective lens 12a and screwed into the female thread 1e of the convex mirror 1 as shown in FIG.
As shown in (d), the screw portion 1f may be formed integrally with the convex mirror 1 and screwed into the female screw portion 12e of the objective lens 12a.
Alternatively, a stud may be screwed into a tapped hole formed in one of the convex mirror 1 and the objective lens 12a and adhered, and the other end of the stud may be screwed into the other screw hole. In FIG. 1, reference numeral 1b denotes a lid for closing the upper part of the convex mirror 1.

FIG. 3 shows an image taken by using such an image pickup apparatus. In the figure, a region A is a portion having an image, and a region B is a portion having no image. Convex mirror 1 and objective lens 12a
8, the area of the region B as the non-image portion increases accordingly.

(B) Second Embodiment Next, a second embodiment will be described. As shown in FIG. 4, in this embodiment, not only the front side (lower side) of the convex mirror 1 but also the back side (upper side) of the convex mirror 1 can be photographed.

As shown in the figure, an objective lens 15 is provided on the convex mirror 1 instead of the lid. An optical path for guiding light incident on the objective lens 15 from the rear side of the convex mirror 1 to a CCD image pickup device (not shown) of the CCD camera 12 is formed inside the convex mirror 1. That is, as shown in the figure, the convex mirror 1 has a hollow interior and a hole 1 in the center.
c is formed and a cylindrical portion 1d protruding downward is formed. On the other hand, a circular groove 12b is formed on the upper surface of the objective lens 12a, and the cylindrical portion 1b is formed in the circular groove 12b.
d is fitted and adhered.

In addition, an image obtained by reflection from the convex mirror 1, that is, an image below the convex mirror 1 and an image obtained by light incident on the objective lens 15, that is, an image above the convex mirror 1 are overlapped. Is set. That is, as shown in FIG. 4, the angle of view of the convex mirror 1 is α, while the angle of view of the objective lens 15 is β, and the dotted portions are overlapping portions. Then, in order to prevent parallax from occurring at the overlapping portion, the NP point P of the convex mirror 1 and the NP point Q of the objective lens 15 are set.
Are set to be the same point.

FIG. 3 shows an image obtained by using such an image pickup apparatus.
It will be described based on. In the first embodiment, the region B is a portion without an image. In the second embodiment, light on the back side of the convex mirror 1 is incident on the convex mirror 1 via the objective lens 15, and the light passes through the hole 1c and the objective lens 12a. 3 to the area B of the CCD image sensor (not shown in FIG. 4) 12c. Therefore, the imaged portion on the back of the convex mirror 1 is shown in the area B.

In the same manner as in the first embodiment, a wide-area image (image on the front side of the convex mirror 1) with an angle of view α of 360 degrees is obtained in the area A, while a wide-area image of a substantially semispherical sphere with an angle of view β is obtained in the area B Image on the back side of the convex mirror 1) is obtained,
By separating and bonding the two images B by computer image processing, it is possible to obtain a wide-angle image of a substantially celestial sphere excluding a portion that becomes a blind spot due to the presence of the CCD camera 12. Since the NP point P and the NP point Q are set to be the same point, parallax does not occur in a portion where images overlap each other.

It should be noted that, in the embodiment, N
The case where the P point coincides with the NP point of the second imaging means has been described. However, if any one NP point is arranged in the other NP point area, the occurrence of parallax is suppressed to a negligible level. Can be.

[0020]

As can be seen from the above description, claim 1
According to the imaging devices of the first to third aspects, since the convex mirror is fixed to the objective lens, it is not necessary to use a transparent cylinder as in the related art, and the number of components can be reduced. Since the transparent tube is not used, there is an effect that a light-shielding rod for blocking light reflected on the inner peripheral surface of the transparent tube and incident on the camera is necessarily unnecessary. Further, the size of the imaging device is reduced in the axial direction, so that the size of the imaging device is reduced.

According to the image pickup apparatus of the present invention, since the second objective lens and the optical path are provided, a blind spot due to the presence of the camera itself is formed in a central area where no image is formed. You can project video. Therefore, by performing the image processing, it is possible to obtain a wide-range image of a substantially celestial sphere. Further, the NP point of the first image pickup means and the NP point of the second image pickup means
Since one of the NP points is set to be located in the other NP point area, the occurrence of parallax in a portion where the two images overlap can be suppressed to a negligible level. it can.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing Embodiment 1 of an imaging device according to a real name invention.

FIG. 2 is a detailed view of a main part of FIG. 1;

FIG. 3 is an explanatory diagram of an image obtained by an imaging device.

FIG. 4 is a configuration diagram showing Embodiment 2 of an imaging device according to the present invention.

FIG. 5 is a detailed view of a main part of FIG. 4;

FIG. 6 is an explanatory diagram for defining an NP point and an NP point region of the equivalent convex lens according to the present invention.

FIG. 7 is a perspective view of a conventional imaging device.

FIG. 8 is a diagram illustrating the operation of a conventional imaging device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Convex mirror 10 ... Adhesive 11 ... Screw 12 ... Camera 12a ... Objective lens

Claims (8)

[Claims] 1. An image pickup apparatus comprising: a convex mirror; and a first image pickup unit arranged opposite to the convex mirror and including a first objective lens and an image pickup unit for taking an image of a portion to be photographed on the front side with respect to the convex mirror. An imaging apparatus, wherein the convex mirror and the first objective lens are fixed. 2. The imaging device according to claim 1, wherein a screw member is used for the fixing. 3. The imaging device according to claim 1, wherein an adhesive is used for the fixing. 4. An optical path for guiding a light from the second objective lens to substantially the center of the imaging unit, wherein a second objective lens for photographing an object to be imaged on the rear side of the convex mirror is provided on the rear side of the convex mirror. 4. The imaging apparatus according to claim 3, wherein the second imaging means is formed on the convex mirror, and images from the respective imaging units are pasted together to obtain a wide-range image. 5. The imaging apparatus according to claim 4, wherein the imaging unit uses an imaging device. 6. The imaging apparatus according to claim 5, wherein a video substantially at the center of the imaging unit and a video outside the video image are set so as to overlap each other. 7. A principal ray passing through a Gaussian region is selected from principal rays passing through centers of apertures provided in the first and second imaging means, and a linear component in the object space of the principal ray is extended. A point that intersects the optical axis is set as an NP point, and an inside of a sphere centered on the NP point is set as an NP point area, and one of the NP points of the first imaging unit and the second imaging unit is set. 7. The image pickup apparatus according to claim 6, wherein the setting is made so as to be arranged in the other NP point area. 8. The radius dimension of the NP point area is approximately 20 mm
The imaging device according to claim 7, wherein: