JPS63195631A - Method for focusing image system - Google Patents

Abstract

PURPOSE:To facilitate the focusing of an objective and to make its magnifica tion constant by allowing a lens barrel to move in two axial directions parallel to the light receiving surface of a camera with the degree of freedom while holding its optical distance constant. CONSTITUTION:The lens barrel 3 is supported movably in the area of the light receiving surface of the camera 2 in parallel to the light receiving surface and the lens barrel 3 is bent by 90 deg. at a proper position and a reflecting mirror 6 is provided at the bend at 45 deg. to the optical axis of the objective 5. Then the lens barrel 3 is moved in parallel to form an image on the light receiving surface of the camera 2. Consequently, while fixing the camera 2, the image can be focused on an observing object point and the handling is facilitated. Further, the optical distance between the objective lens 5 and the light receiving surface can be held constant, so the magnification is made constant at all times.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a method for focusing an imaging system.

(Prior Art) An image system including a camera, a lens barrel attached to the camera, and an objective lens attached to the lens barrel to form an image on the light-receiving surface of the camera is as shown in FIG. An integrated type in which a camera 20, a lens barrel 21, and an objective lens 22 are integrated into the camera, and these are moved together when focusing on the object point A or B to be observed, or As shown in FIG. 5, the camera 20 and lens barrel 21 are fixed, and the objective lens 22 is movable along the optical axis. When focusing on object point A or B to be observed, only the objective lens 22 is used. There is a lens-driven type that moves the

(Problems to be Solved by the Invention) However, in the former case, it is necessary to move the entire image system when focusing on the object point to be observed, so a large-scale mount (stage) is required.
It takes time and effort to move the camera, requires a precision mechanism for the mount, has low strength, is not suitable for precise and high-precision machinery, and is disadvantageous in terms of transportation. There is a problem.

The latter is advantageous in terms of strength and transportation, and is highly reliable, but if you move the position of the objective lens when focusing on the object point to be observed, the distance from the lens to the light receiving surface ( There is a problem in that the optical distance (hereinafter referred to as optical distance) changes, and as a result, it affects the magnification of the image formed on the camera, making it unsuitable for high-precision shape measurement, image processing, etc.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a focusing method for an image system that is highly accurate, has excellent durability, and is easy to handle.

(Means for Solving the Problems) In order to achieve the above object, according to the present invention, a camera;
In a focusing method for an image system comprising a lens barrel attached to the camera and an objective lens attached to the lens barrel to form an image on the light receiving surface of the camera, the lens barrel is placed relative to the light receiving surface of the camera. The lens barrel is bent at a right angle at an appropriate position, and a reflecting mirror is placed at the corner at an angle of 45° with respect to the optical axis of the objective lens. is provided, and the lens barrel is moved in parallel to focus,
The image is formed on the light receiving surface of the camera.

(Function) The optical distance from the objective lens of the lens barrel to the light-receiving surface remains constant and does not change even when the lens barrel is moved parallel to the light-receiving surface of the camera. That is, the lens barrel can be moved with degrees of freedom in two axial directions parallel to the light-receiving surface of the camera while keeping its optical distance constant. As a result, the imaging system can easily focus the objective lens, and the size of the image formed on the light-receiving surface, that is, the magnification, can be kept constant.

(Example) An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a schematic configuration of an image system to which the present invention is applied. The image system 1 is composed of a camera body 2 and a lens barrel 3, and the light receiving section of the camera body 2 displays the brightness and darkness of each part of the subject to be imaged. A photoelectric conversion element, for example, an image pickup tube 4, which converts into an electrical signal proportional to , is provided. That is, the light receiving surface of the camera 2 is constituted by the image pickup tube 4.

The lens barrel 3 is bent at a right angle approximately at the center thereof, an objective lens 5 is attached to the tip of the lens barrel 3a on the minus side, and a reflecting mirror 6 is arranged at the corner of the bent portion. The objective lens 5 is arranged so that its optical axis is aligned with the axis of the lens barrel 3a. Also,
The reflecting mirror 6 is arranged on the optical axis of the objective lens 5, with the reflecting surface 6a forming an angle of 45'' with respect to the optical axis of the objective lens 5, and bends the optical axis of the objective lens 5 by 90 degrees. Also within this lens barrel 3b, which is guided into the lens barrel 3b on the other side, the optical axis of the objective lens 5 coincides with the axis of the lens barrel 3b.

The lens barrel 3 is arranged in parallel with the open end 3C of the other lens barrel 3b facing the light-receiving surface 4a of the image pickup tube 4, and is positioned within the light-receivable area of the light-receiving surface 4a of the image pickup tube 4 by a support mechanism (not shown). Supported for translational movement. That is, the lens barrel 3b is movable in two axes: an X-axis parallel to the light-receiving surface 4a of the image pickup tube 4, and a Y-axis (direction perpendicular to the plane of the drawing). This results in
The objective lens 5 is arranged along with the lens barrel 3 in the X and Y axis directions, that is, in the
- It is movable within the Y plane. By moving the lens barrel 3 in the X-axis direction, it is possible to focus the object using the objective lens 5. The length of the lens barrel 3 is constant, so there is no change in the optical distance due to the focusing, and the size of the object imaged on the light receiving surface 4a of the image pickup tube 4, that is,
The magnification is always constant. Note that the moving distance of the objective lens 5 during focusing is small, and therefore the amount of movement of the lens barrel 3 in the X-axis direction is small. Furthermore, the amount of movement of the lens barrel 3 in the Y-axis direction is also small.

The action will be explained below.

First, when observing the object point A on the optical axis of the objective lens 5, the lens barrel 3 is moved downward in the figure along the X-axis direction to focus on the object point A. As a result, the objective lens 5 moves to the object point A.
is imaged on the light-receiving surface 4a of the image pickup tube 4. Next, when observing an object point B located coaxially with the object point A and separated from the objective lens 5 by a distance ΔX from the object point A, Rotate lens barrel 3 to
The object point B is focused by moving along the axial direction to the position indicated by the two-point chain NlX3°. Thereby, the objective lens 5 forms an image of the object point B on the light receiving surface 4a of the image pickup tube 4. Therefore, object point A and object point B can be easily focused. At this time, since the distance from the objective lens 5 to the light-receiving surface 4a, that is, the optical distance, is constant, the magnifications of the object points A and B imaged on the light-receiving surface 4a are the same.

Such an image system 1 can be used, for example, as an image processing device during fusion splicing in a core direct-view fusion splicer that fusion splices optical fibers. That is, as shown in FIG. 2, a reflecting mirror, for example, a plane mirror 11, is placed on one side of the connecting portion 10a of the optical fiber core IO at a slight distance from the connecting portion 10a.
An imaging system 1 is placed at a predetermined position on the opposite side of the plane mirror 11 and diagonally above the connecting portion tOa of the core 10. and,
This imaging system l is in the longitudinal direction (Z-axis direction) of the core lO.
The movable X-Y plane of the objective lens 5 is perpendicular to the object lens 5, and the optical axis of the objective lens 5 is
It is placed so as to intersect with a.

This image system 1 allows the connecting portion tOa of the core 10 to be
When observing, first, the lens barrel 3 is moved along the X-axis direction, the objective lens 5 is focused on the connecting portion 10a, and the connecting portion 10a is observed.

Next, the lens barrel 3 is moved in the Y-axis direction and the X-axis direction as shown by the two-dot chain line to create a virtual image of the connecting portion 10a by the plane mirror 11, that is, at a distance Δy in the Y-axis direction from the connecting portion 10a, in the x-axis direction. The objective lens 5 is focused on a virtual object point 10a° located a distance ΔX away from , and the virtual object point 10a° is observed. This allows the image system 1 to connect to the core IO connection 1.
0a can be observed from two directions along the X-axis and Y-axis directions, and the connection state of the connection portion 10a can be observed with high precision.

In the above embodiment, a configuration was described in which the entire lens barrel 3 is moved parallel to the light receiving surface 4a of the image pickup tube 4 of the camera 2 to focus the objective lens 5, but the present invention is not limited to this. If the amount of movement of the objective lens 5 is small, for example, as shown in FIG.
The lens barrel 8b is divided into two parts:
Fix the rear end to camera 2, and attach 8a to the image tube (not shown)
The lens barrel 8a is arranged parallel to the light receiving surface along the X-Y plane in the same manner as described above, and the rear end of the lens barrel 8a is arranged to face the front end of the lens barrel 8b. A configuration may be adopted in which the focus of the objective lens 5 is adjusted only by operation.

(Effect of the invention)
4. As explained above, according to the present invention, there is provided an image system including a camera, a lens barrel attached to the camera, and an objective lens attached to the #ti lens barrel to form an image on the light receiving surface of the camera. In the focusing method, the lens barrel is supported so as to be movable in parallel to the light receiving surface of the camera and within the area of the light receiving surface, and the lens barrel is bent at a right angle at an appropriate position and bent at a right angle to the corner. A reflecting mirror is provided at an angle of 456 with respect to the optical axis of the objective lens, and the lens barrel is moved in parallel to focus,
Since the image is formed on the light-receiving surface of the camera, it is possible to focus on the object point to be observed while the camera remains fixed, and handling is easy.
Since the optical distance between the objective lens and the light-receiving surface can be kept constant, the magnification can always be kept constant, making it possible to perform highly accurate shape measurement, image processing, etc.

In addition, the image system can be constructed to be robust, reliability is improved, and transportation is also advantageous.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of an image system to which the focusing method of an image system according to the present invention is applied, and FIG.
FIG. 3 is a perspective view showing another embodiment of the focusing method of the image system shown in FIG. 1; FIG.
FIG. 5 is a perspective view showing a conventional imaging system. 1...Image system, 2...Camera, 3.8...
Lens barrel, 4... Image pickup tube, 5... Objective lens, 6.11
... Reflector, 10... Optical fiber core, 10a.
...Connection part. Figure 1 Figure 4

Claims (1)

[Claims] In a focusing method for an image system including a camera, a lens barrel attached to the camera, and an objective lens attached to the lens barrel to form an image on a light receiving surface of the camera, the lens barrel is connected to the light receiving surface of the camera. The lens barrel is supported so as to be movable parallel to the surface and within the area of the light-receiving surface, and the lens barrel is bent at a right angle at an appropriate position, and an angle of 45° is formed at the corner with respect to the optical axis of the objective lens. A focusing method for an image system, characterized in that a reflecting mirror is provided, the lens barrel is moved in parallel to focus, and an image is formed on a light-receiving surface of the camera.