JP2006209041A - Panorama lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a panorama lens capable of providing a distinct image, having a wide angle of view, and catching a subject in front of a camera so that it can also be utilized for an endoscope, by improving the shape of conventional type panorama lens. <P>SOLUTION: The panorama lens is constituted so that its upper surface is a 1st concave reflection surface, its bottom surface is a 2nd concave light transmissive surface, and its side surface is a barrel-shaped light transmissive surface. The 1st concave reflecting surface and the 2nd concave light-transmitting surface are set to be any of a spherical surface, an elliptical rotating body surface, a parabolic rotating body surface and a hyperbolic rotating body surface, and the barrel-shaped light-transmitting surface is set as a surface, formed of points which have the sum of the distances from the intersection O of the 2nd concave light-transmitting surface with the center axis of the barrel-shaped light-transmitting surface to an arbitrary point on the 1st concave reflecting surface when light is projected from the intersection O toward the 1st concave reflecting surface and the distance of reflected light from the 1st concave reflecting surface to the barrel-shaped light-transmitting surface. The panorama lens is equipped with a light-transmitting surface at the center part of the 1st concave reflecting surface and catches the front of the camera in the field of vision, by means of incorporating a wide-angle lens. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a panoramic lens for inputting and outputting 360 ° omnidirectional images.

2. Description of the Related Art Conventionally, for a periscope such as a submarine, there is a method characterized in that image distortion is canceled by using a panoramic lens having a barrel-shaped outer shape and a conical mirror as an objective lens and an eyepiece. (For example, refer to Patent Document 1). The panoramic lens is formed of a conical mirror with an elevation angle of 45 ° and a barrel-shaped side surface with the same vertical and horizontal curvature radii. The angle of view around the rotation axis is 360 °, but the angle of view of the elevation angle and depression angle are both added. However, it was about 30 °, and there was a drawback that it was a blind spot when looking at the sky or the like. This disadvantage is due to the use of a conical mirror, and if the reflecting mirror is curved, the angle of view increases, but if the side is not an aspherical light-transmitting surface matched to the reflecting mirror, it will not form an image, so a clear image will be It was not obtained and the shape of both surfaces was not specified.

In recent years, an omnidirectional camera or omnidirectional sensor has a so-called surface reflecting mirror such as a convex mirror or a hyperboloidal mirror, and forms an image of 360 ° omnidirectional light on a camera lens facing the surface reflecting mirror. Was developed. Since this method does not require the aspherical light-transmitting surface, it is effective for solving the above-described problem of no image formation. However, such an omnidirectional camera and omnidirectional sensor need to be connected by a transparent cylinder to fix the surface reflecting mirror, but stray light enters the transparent cylinder and affects the image quality. There is a problem of giving. The cause is that the light beam incident from the outside to the inside of the transparent cylinder is disturbed by stray light due to reflection or refraction at the outer and inner surfaces of the transparent cylinder. In order to deal with such a problem, an invention has been invented in which a rod-like body for preventing internal reflection of a cylindrical body is provided at the top of a surface reflecting mirror. However, there is a drawback that the front of the camera cannot be seen in addition to the complicated structure. (For example, refer to Patent Document 2).

In addition, conventional omnidirectional cameras, omnidirectional sensors and panoramic lenses using surface reflectors have not been put into practical use because they can capture 360 degrees around the rotation axis and the subject in front of the camera at the same time. It is inconvenient to use.

Japanese Patent No. 23804 Japanese Patent No. 3086204

An object of the present invention is to improve the shape of a conventional panoramic lens to obtain a clear image with a wide angle of view, and to capture a subject in front of the camera so that it can be used for an endoscope.

The present invention for solving the above problems is as follows.
(1) A panoramic lens having an upper surface as a first concave reflecting surface, a bottom surface as a second concave light transmitting surface, and a side surface as a barrel light transmitting surface, wherein the first concave reflecting surface and the second concave light transmitting surface are: It is any one of a spherical surface, an elliptical rotator surface, a parabolic rotator surface, and a hyperbolic rotator surface, and the barrel-shaped translucent surface is a first concave reflective surface from an intersection 0 between the second concave translucent surface and its central axis. The sum of the distance from the intersection point 0 to an arbitrary point on the first concave reflection surface and the distance from the first concave reflection surface to the barrel-shaped light transmission surface when projected toward is equal. A panoramic lens (hereinafter, referred to as a first invention) characterized by being a surface formed by dots.
(2) The first concave reflective surface of the first invention is characterized in that at least the optical axis is a light-transmitting surface for seeing through the subject when the panoramic lens is used in a camera. Panorama lens (hereinafter referred to as second invention).
(3) The panoramic lens of the second invention comprises a concave lens used on the optical axis of the light transmitting surface of the first concave reflecting surface (hereinafter referred to as the third invention). ).

(1) Since the shape of the panoramic lens is specified according to the first invention, the light beam that has entered from the barrel-shaped light transmission, reflected by the first concave reflection surface, and passed through the second concave transmission surface has regularity. Diffuses and forms a virtual image in the panoramic lens. The light beam connecting the virtual image can be imaged by a camera or other optical system, and a clear image can be obtained. Compared to the conventional one, the angle of view of this panoramic lens is increased to about 90 ° by adding the elevation angle and the depression angle, and the angle of view around the rotation axis is 360 ° as in the conventional case. Compared to the one using a surface reflector and a transparent cylinder, the number of surfaces that cause stray light is halved and the influence on image quality is reduced. Moreover, since the number of parts is reduced, it is advantageous for downsizing. Mass production is easy if the mold is used.
(2) The second invention makes it possible to capture the subject in front of the camera with an angle of view of about 90 °.
(3) According to the third invention, it becomes possible to focus the light beam incident from the barrel-shaped light transmitting surface and the light beam incident from the light transmitting surface at the center of the first concave reflecting surface. It can be captured as a single image.

1 to 7 show a first embodiment of the first invention. FIG. 1 is a side view, FIG. 2 is a plan view, FIG. 3 is a bottom view, and FIG. 4 is a line AA in FIG. FIG. 5 is a partially enlarged view of FIG. 4, FIG. 6 is a detailed view showing the shape of the top, side and bottom surfaces of the panoramic lens, and FIG. 7 is an optical path diagram showing the function of the panoramic lens.

In the figure, the panoramic lens 12 is formed of a transparent material. The material may be colored as long as it does not block all light.

In the figure, the top surface 1 and the bottom surface 2 are spherical. Further, assuming that the radius of curvature of the upper surface 1 is R1 and the distance from the reference point 0 to the center point of the upper surface 1 is D, R1 to D is 3 to 5. This ratio may be arbitrary as long as D is larger than R1. Further, assuming that the curvature radius of the bottom surface 2 is R2 and the refractive index of the material forming the panoramic lens 12 is n, the numerical value of R2 is determined by the equation (1).

Number 1

R2 = R1 / (n-1)

In the figure, a connection portion 6 with another optical system is provided to facilitate connection with another optical system 14 such as a camera. These connection methods are not particularly limited.

In FIG. 5, the upper surface 1 forms a reflecting surface facing the bottom surface 2 side. The antireflection coating layer 5 such as matte coating is formed on the reflection surface on the reflection coating layer 4 that has been subjected to chrome plating, aluminum plating, silver plating, or vapor deposition thereof.

In FIG. 6, the intersection of the curves representing the upper surface 1 and the side surface 3 is T, and the distance from the reference point 0 to an arbitrary point on the upper surface 1 when projected from the reference point 0 toward the upper surface 1 is k1 and k2, respectively. , K3,... Kn, and the distance from the corresponding upper surface 1 to the side surface 3 of the reflected light is h1, h2, h3,... Hn, the side 3 has the sum of both distances equal to the line segment 0T. A surface formed by dots. See Equation 2.

Number 2

0T = k1 + h1 = k2 + h2 = k3 + h3 =... = Kn + hn

FIG. 7 is an optical path diagram showing the function of the first invention. In FIG. 7, a subject 7 connects a virtual image to a virtual image point 9, and a subject 8 connects a virtual image to a virtual image point 10.

FIG. 8 shows a side view of the second embodiment of the second invention. In FIG. 8, when the light projected from the reference point 0 is reflected by the upper surface 1 and diffused to the bottom surface 2, the area of the reflecting surface that illuminates the area of the connection portion 6 with the other optical system is expressed by the upper surface 1 part light transmitting surface 9 The size of. This makes it possible to capture the subject in front of the camera. A reflective coating layer 4 and an antireflection coating layer 5 are formed on the reflective surface of the upper surface 1.

FIG. 9 shows a plan view of the second embodiment of the second invention and corresponds to FIG.

FIG. 10 shows a side view of the third embodiment of the third invention. In the drawing, the incident light from the upper surface 1 and the incident light from the side surface 3 are matched by using the additional wide-angle lens 13. The material of the additional wide-angle lens 13 may not necessarily be the same as that of the panoramic lens 12, and may be composed of two or more optical systems.

In FIG. 10, another optical system 14 such as a camera is provided on the bottom surface 2 side, and its focus is adjusted to the position of the virtual image point of the panoramic lens 12.

It is a side view of Example 1 of the 1st invention. It is a top view of Example 1 of the 1st invention. It is a bottom view of Example 1 of the 1st invention. It is AA sectional drawing of Example 1 of 1st invention. It is the elements on larger scale which show the coating layer given to the upper surface. It is detail drawing which specifies the shape of Example 1 of 1st invention. It is an optical path diagram which shows the function of Example 1 of 1st invention. It is a side view of Example 2 of 2nd invention, and is a figure corresponding to FIG. It is a top view of Example 2 of 2nd invention, and is a figure corresponding to FIG. It is a side view of Example 3 of 3rd invention, and is a figure which shows a structure with an additional wide-angle lens and another optical system.

Explanation of symbols

0 Reference point 1 Upper surface 2 Bottom surface 3 Side surface 4 Reflective coating layer 5 Antireflection coating layer 6 Connection portion with other optical system 7 Subject 8 Subject 9 Virtual image point 10 Virtual image point 11 Upper surface 1 portion Translucent surface 12 Panorama lens 13 Additional wide angle lens 14 Other optical systems

Claims (3)

A panoramic lens having an upper surface as a first concave reflection surface, a bottom surface as a second concave transmission surface, and a side surface as a barrel transmission surface, wherein the first concave reflection surface and the second concave transmission surface are spherical and elliptical. It is any one of a rotating body surface, a parabolic rotating body surface, and a hyperbolic rotating body surface, and the barrel-shaped translucent surface is directed from the intersection 0 between the second concave translucent surface and its central axis toward the first concave reflective surface. Formed at the point where the sum of the distance from the intersection 0 to an arbitrary point on the first concave reflecting surface and the distance from the first concave reflecting surface to the barrel-shaped translucent surface when projected is equal. A panoramic lens characterized by the fact that it is a surface to be turned. 2. The panoramic lens according to claim 1, wherein the first concave reflecting surface is a light-transmitting surface for seeing through a subject when the panoramic lens is used in a camera. The panoramic lens according to claim 2, further comprising a concave lens used on the optical axis of the translucent surface of the first concave reflecting surface.

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