JPH0627393A - Observation device - Google Patents

Abstract

PURPOSE:To easily adjust the focal point position of an objective lens at an observation device side. CONSTITUTION:A main body 2 is made of a double tube construction. A solid- state imaging pick-up device 3 is incorporated in the tip section of an inner tube body 2B and the one end section of a light emitting side optical fiber 15 is incorporated in a ring shaped gap 14 formed between an outer tube body 2A and the inner tube body 2B. A mirror tube 4 is made of a double tube construction by a lens holding tube 20 and a focal point adjustment tube body 21. An objective lens 5 is incorporated in the tube 20 and fitted so as to prevent the rotation by rotation preventing pins 12a and 12b and long holes 23a and 23b in the body 2B. The body 21 is provided with a light-emitting side optical fiber 29 and is integrally connected to the tube 20 by a screwing and is press- fixed to the front end surface 7 of the body 2 by a connecting section member 6. When the member 6 is released and the body 21 is rotated, the rotation is converted to a linear motion in the optical axis direction of the tube 20 by the pins 12a and 12b and the holes 23a and 23b. Thus, the focal point position of the lens 5 is adjusted back and forth.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an observation device suitable for application to small video cameras, endoscopes and the like.

[0002]

2. Description of the Related Art In recent years, in the field of industrial machines, an image recognition device using a video camera has been widely used in combination with the development of solid-state image pickup devices. Also in the field of microscopes, there are many application examples in which a magnifying objective lens is incorporated in a video camera to observe a minute object. These observation devices have a main purpose of observing objects that are relatively close to each other, and both of them also use an illumination device according to each purpose. For example, in the case of an image recognition device, an area to be observed for performing image processing is uniformly illuminated to ensure sufficient brightness for recognizing an object and prevent erroneous recognition due to uneven brightness. . Further, in the case of a video camera for a microscope intended for enlargement, since the observation optical system is generally dark and the observation object is minute, the illumination light is condensed in a minute range to secure a desired brightness. . Furthermore, even in the case of an endoscope that incorporates an image fiber or a video endoscope that captures images with a microminiature solid-state image sensor, it is intended to observe the inside of a dark tube or human body that is not illuminated normally.
It is equipped with an illumination device that ensures sufficient brightness for observation and illuminates a wide field of view. When observing a near object, this type of optical observation apparatus arranges an objective lens on the front side on the same optical axis as an optical fiber as an image transmission means or a solid-state image sensor, and an optical system for illumination. Depending on the purpose, it is installed in the vicinity of the objective lens, and the object is placed on the end face of the optical fiber or the image plane such as the image plane of the solid-state image sensor.
An image is formed using an objective lens.

As a device provided with an illumination optical system in the vicinity of the objective lens, for example, Japanese Examined Patent Publication No. 4-20615, "Light guide device for illumination in magnified image pickup device" is known. In this light guide device for illumination, a plurality of minute optical fiber tip light emitting portions are arranged in a lens barrel in an annular shape coaxially with the light emitting portion, and the light emitted from the optical fibers is provided on the lens barrel tip surface. The light is guided into the hemispherical light-guiding cap, and the light guided into this cap is repeatedly totally reflected in the cap so that it is projected from the inner peripheral surface of the small hole formed in the center of the cap onto the surface of the subject. It is composed. In this case, the light guide cap is formed so as to be in focus with the subject contacting the outer surface of the cap in the small hole portion in relation to the optical system. That is, the above-mentioned light guide device for illumination defines the focus position by the distance from the spherical center of the light guide cap to the small hole, that is, the radius, and by bringing the cap into contact with the subject, the subject is surely placed at the focus position. It has the advantage that it can be installed. However, in such an apparatus, the illumination range is limited to a small range of small holes, and if the focus position is fixed, it is not possible to freely adjust the observation distance to capture an image. was there.

Therefore, for example, Japanese Patent Publication No. 4-254, in which the focus position can be freely adjusted, is disclosed.
The publication "Endoscope" is known. This endoscope uses a mechanism in which a lens frame holding an objective lens is slidably housed in an optical axis direction in a housing part formed at a distal end configuration part, and a mechanism for sliding the lens frame by an operation wire is used for focusing. It is configured to adjust the position of.

[0005]

However, in the focus adjusting mechanism in the above-mentioned conventional endoscope, since the push-pull of the operation wire is performed by the remote operation from the operation section which is the main body of the endoscope, the objective lens. However, there is a drawback in that it is not possible to attach and detach the endoscope from the distal end configuration part and replace it according to the application. Further, since the focus adjustment is performed only by pushing and pulling the operation wire, there is a drawback that the focus position changes depending on the bending degree of the endoscope insertion portion. Furthermore, since the connecting portion of the operation wire is engaged with the locking portion formed on the outer peripheral surface of the lens frame, the outer peripheral surface of the lens frame needs to be formed on the outer peripheral surface of the lens frame in order to realize a smaller tip end portion. There is no choice but to arrange the illumination optical system in the vicinity of the protrusion-shaped locking part, and the structure is naturally eccentric with the optical axis of the observation optical system. There is also a drawback that uneven illumination occurs due to the shift of the optical axis of the system. In addition, in order to eliminate the illumination unevenness caused by the deviation of the optical axis with this mechanism, in order to form the optical axis of the illumination system and the observation system on the same axis, the projection system is formed on the outer surface of the lens frame from the observation system optical axis. Since the illumination optical system has to be arranged on the circumference of a radius exceeding the distance to the upper end of the locking portion formed in the above, there is a drawback that the outer shape becomes large.

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to easily replace a lens and to use it for various purposes and to adjust a focus. An object of the present invention is to provide an observation device that can be freely operated and is provided with an illumination means.

[0007]

The present invention has been made to achieve the above object, and the first invention thereof is a main body incorporating an image transmitting means for electrically or optically transmitting an image of an object. A lens barrel having a built-in objective lens, a connecting member for separably connecting the main body and the lens barrel, and an illumination optical system for illuminating an object. The main body has a large-diameter cylindrical portion and the image transmitting means. And a small-diameter cylindrical portion projecting forward from the large-diameter cylindrical portion integrally provided with an anti-rotation pin on the outer peripheral surface, and the lens barrel accommodates an objective lens and is provided on the outer peripheral surface. A male holding portion, an axially elongated hole into which the rotation preventing pin of the main body is inserted, a lens holding barrel into which the small diameter tubular portion of the main body is inserted, and an internal thread portion on the inner peripheral surface. The lens holding tube is stored by screwing the male thread of the lens holding tube into the female thread. , In which is composed of a focus adjusting cylindrical body is joined and fixed to the body by the coupling member the rear end face abuts on the large-diameter cylindrical portion front end face of the body. Second
In the first aspect of the invention, in the illumination optical system, one end is connected to the light source, and the other end is arranged in an annular shape along the inner peripheral surface of the large-diameter cylindrical portion of the main body, and the end surface is a large-diameter cylinder. A light emitting side optical fiber facing the front end face of the section, and an emitting side light guide body arranged in an annular shape in the focus adjusting barrel of the lens barrel, each end face of which faces the end face of the focus adjusting barrel, and The light guide and at least the tip of the optical fiber are arranged coaxially with the image transmission means and the objective lens.

[0008]

In the present invention, when the rotation of the focus adjusting cylinder forming the lens barrel is transmitted to the lens holding cylinder connected by screwing the same with the lens holding cylinder, the lens holding cylinder has a long hole and a rotation preventing member. Since rotation is prevented by the pin, it makes a linear movement in the optical axis direction and adjusts the focal position of the objective lens. The connecting member detachably connects the lens barrel to the main body.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the drawings. FIG. 1 is a sectional view showing an embodiment of an observation apparatus according to the present invention, FIG. 2 is an external perspective view of the same, and FIG. 3 is an exploded perspective view of a main body and a lens barrel. This embodiment shows an example applied to a small video camera. In these figures, reference numeral 1 is an observing device that constitutes the tip of a video camera. This observing device 1 includes a main body 2 that houses a solid-state image sensor 3 as an image transmission means and an objective lens 5 that is housed in the main body 2. It includes a lens barrel 4 which is detachably attached, and a connecting member 6 which detachably connects and fixes the main body 2 and the lens barrel 4.

The main body 2 has a large-diameter outer cylindrical body (large-diameter cylindrical portion).
2A and a rear end portion of the outer cylinder body 2A that is coaxially inserted into a small diameter inner cylinder body (small diameter cylinder portion) 2B to form a double cylinder structure. The lens barrel 4 is connected and fixed to the lens 7 by a connecting member 6. The outer cylindrical body 2A has a male screw portion 8 on a part of its outer peripheral surface and is connected to a camera controller portion (not shown) via a flexible tube 9. The inner tubular body 2B has a front end portion 210 that projects forward from the front opening of the outer tubular body 2A.
The cover glass 11 is formed with a diameter smaller than that of the rear end portion 211 inserted into A, and the cover glass 11 is fitted into the opening portion 10 opened at the center of the front end surface and fixed by an adhesive,
Further, the solid-state image pickup device 3 is also closely fixed to the inner surface thereof by an adhesive. One end of the wiring 13 is connected to the solid-state image pickup device 3, and the other end of the wiring 13 is connected to the camera controller section through the inside of the flexible tube 9. In addition, a pair of rotation preventing pins 12a and 12b are provided at the middle portion of the outer peripheral surface of the front end portion 210 in the circumferential direction.
Deviated by a degree and projected integrally. On the other hand, the rear end portion 21
An annular gap 14 is provided between the outer peripheral surface of the outer cylindrical body 1 and the inner peripheral surface of the outer cylindrical body 2A. In the annular gap 14, the light from the light source is emitted from the lens barrel 4. Side optical fiber 29
The optical fiber 15 on the light-emission side is introduced. The light emitting side optical fiber 15 is composed of a large number of fine optical fiber groups having a diameter of about 50 μm, and the tip end surface of the end portion inserted into the gap 14 is the front end surface 7 of the outer cylindrical body 2A.
Is exposed to the outside, and the other ends are bundled into one and pass through the flexible tube 9 to be connected to a light source (not shown).

Like the main body 2, the lens barrel 4 has a double-barreled structure including a lens holding barrel 20 and a focus adjusting barrel 21, and the focus adjusting barrel 21 itself is double. The inner cylinder 21a and the outer cylinder 21b are formed by forming a cylindrical structure. The lens holding cylinder 20 accommodates and holds the objective lens 5 in the vicinity of the opening on the inner front end side, and has an external thread on the outer peripheral surface thereof and an axis line formed corresponding to the rotation preventing pins 12a and 12b of the main body 2. A pair of long holes 23a long in the direction,
23b, and the small diameter portion 21 of the inner cylindrical body 2B of the main body 2
0 is slidably fitted and has the pins 12a and 12b.
The rotation is prevented by the long holes 23a and 23b. The male screw portion 22 is formed on a portion of the outer peripheral surface of the lens holding cylinder 20 in which the objective lens 5 is housed, and has a long hole 23a,
Reference numeral 23b is formed on the rear end side of the outer peripheral surface, and its rear end is open to the rear end surface of the lens holding cylinder 20 so that the rotation preventing pins 12a and 12b can be inserted. The outer diameter of the inner cylinder 21a of the focus adjustment cylinder 21 is substantially equal to the outer diameter of the large diameter portion 211 of the inner cylinder 2B of the main body 2, and the inner diameter is substantially equal to the outer diameter of the lens holding cylinder 20. It is set to be slightly larger than this, and the lens holding cylinder 20 is located near the front end of the inner peripheral surface.
A female screw portion 24 that is screwed into the male screw portion 22 is formed. Further, a retaining ring 25 is fitted and fixed on the front side of the female screw portion 24, thereby preventing the lens holding barrel 20 from coming off from the inner barrel 21a. The outer cylinder 21
b has an inner diameter that is substantially the same as the inner diameter of the outer cylindrical body 2A, and a flange portion 26 that prevents the connecting member 6 from coming off at the rear end portion of the outer peripheral surface.
A retaining ring 27 is provided. The inner cylinder 21
An annular gap 28 is formed between a and the outer cylinder 21b, and the emission side optical fiber 29 is provided in the annular gap 28.
Is built in. The emission side optical fiber 29 constitutes the illumination optical system of the observation apparatus 1 together with the emission side optical fiber 15, and, like the emission side optical fiber 15, is composed of a large number of fine optical fibers having a diameter of about 50 μm. The end faces face the openings at both ends of the annular gap 28, respectively. When the rear end face of the emission side optical fiber 29 is brought into close contact with the front end face 7 of the main body 2, the rear end face of the lens barrel 4 is brought into close contact with the front end face of the light emitting side optical fiber 15 in order to reduce loss of light. To be done. The end of the optical fiber 15 on the side opposite to the light source, which is inserted into the annular gap 14, and the optical fiber 29 on the emission side are arranged coaxially with respect to the solid-state imaging device 3 and the objective lens 5. Further, the light guide on the side of the lens barrel 4 is not limited to the optical fiber 29, and may be a cylinder formed of transparent resin or glass and having a light entrance surface and an exit surface.

The connecting member 6 is composed of a nut, and an annular convex portion 6a provided on the inner peripheral surface of the front end portion is located between the collar portion 26 of the focus adjusting cylinder 21 and the retaining ring 27. Is rotatably fitted to the outer peripheral surface of the rear end portion of the focus adjusting cylinder 21, and the female screw portion 30 that is screwed into the male screw portion 8 of the main body 2 is formed on the inner peripheral surface of the rear end portion. When connecting the main body 2 and the lens barrel 4, the small diameter portion 210 of the inner cylindrical body 2B of the main body 2 is fitted in the lens holding cylinder 20 from the rear side so that the rotation preventing pins 12a and 12b and the long holes 23a and 23b are aligned with each other. Then, the connecting member 6 is rotated in the tightening direction and the female screw portion 30 is screwed into the male screw portion 8 of the main body 2 so that the rear end surface of the focus adjusting cylinder 21 becomes the front end surface 7 of the outer cylinder 2A. Assembling is completed by pressing the stepped surface 31 of the inner cylindrical body 2B.

In the photographing apparatus 1 having such a structure, when the focal position of the objective lens 5 is adjusted when observing an object, the connecting member 6 is slightly loosened so that the lens barrel 4 can be rotated with respect to the main body 2. Then, in this state, the focusing cylinder 21 may be manually rotated. Then, the rotation is transmitted to the lens holding barrel 20 via the female screw portion 24 and the male screw portion 22. At this time, the lens holding barrel 20 is prevented from rotating by the rotation preventing pins 12a and 12b and the long holes 23a and 23b. Therefore, the rotational movement of the outer tubular body 21 is converted into the linear movement of the lens holding barrel 20 in the optical axis direction, whereby the focus position of the objective lens 5 can be shifted forward or backward. Therefore, an observation image at an arbitrary position can be obtained according to the distance of the observation object.
Further, when the objective lens having a different focal length depending on the observation object is to be replaced, the lens barrel 4 can be detached from the main body 2 by loosening the connecting member 6 sufficiently to release the screwed connection with the main body 2. Therefore, it can be easily replaced with another lens barrel having an objective lens having a different focal length. Furthermore, in the present invention, unlike the above-mentioned conventional endoscope, the inner cylindrical body 20 constituting the focus adjusting mechanism of the objective lens 5 is provided.
Also, since it is not necessary to provide a protrusion on a part of the outer circumference of the outer cylinder body 21, the light emitting side optical fiber 15 which constitutes the illumination optical system.
And the output side optical fiber 29 can be provided in an annular shape coaxially with the solid-state imaging device 3 and the objective lens 5,
As a result, there are advantages that the device can be downsized and good illumination without illumination unevenness can be obtained.

In the above embodiment, the case where the solid-state image pickup device 3 is used as the image transmission means has been described, but the present invention is not limited to this, and an image (optical) fiber is used to optically transmit the image of the object. Of course, it is also good.

[0015]

As described above, the observing apparatus according to the present invention includes a main body, a lens barrel detachably attached to the main body, a lens holding barrel for accommodating an objective lens in the lens barrel, and a main body. A double cylinder structure is formed by the focus adjusting cylinder body that is connected and fixed to the lens holding cylinder by converting the rotation of the focus adjusting cylinder body into a linear movement by the rotation preventing pin and the elongated hole. Since the focus position of the objective lens is adjusted by moving the focus lens in the direction, adjustment of the focus position is simple and easy, and an observation image at an arbitrary position can be obtained according to the distance of the observation object. Further, it is easy to replace the objective lens with a different focal length, and it is possible to observe a wide range from a reduced image to an enlarged image. Furthermore, in the present invention, since the illumination optical system is arranged in an annular shape on the same axis as the image transmission means and the objective lens, the brightness is uniform and a wide range can be illuminated. Is.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of an observation apparatus according to the present invention.

FIG. 2 is an external perspective view of the same device.

FIG. 3 is an exploded perspective view of a main body and a lens barrel.

[Explanation of symbols]

 2 Main body 3 Solid-state image sensor 4 Lens barrel 5 Objective lens 6 Connecting member 7 Front end face 8 Male screw part 9 Flexible tube 12a, 12b Rotation prevention pin 15 Light emitting side optical fiber 20 Lens holding cylinder 21 Focus adjusting cylinder 22 Male screw part 23a, 23b Long hole 24 Female threaded portion 29 Output side optical fiber 30 Female threaded portion

Claims (2)

[Claims] 1. A body containing an image transmitting means for electrically or optically transmitting an image of an object, a lens barrel containing an objective lens, a connecting member for detachably connecting the body and the lens barrel, and the object. And an illumination optical system for illuminating the front side of the large-diameter cylindrical portion, wherein the main body accommodates the large-diameter cylindrical portion and the image transmitting means, and a rotation preventing pin is integrally projectingly provided on an outer peripheral surface of the main body. And a small-diameter cylindrical portion protruding to the lens barrel, wherein the lens barrel accommodates an objective lens and a male screw portion on the outer peripheral surface,
A lens holding cylinder having an axially elongated hole into which the rotation preventing pin of the main body is inserted, a small diameter cylindrical portion of the main body being inserted, and an internal thread portion on an inner peripheral surface of the internal thread portion. For focus adjustment in which the male thread portion of the lens holding cylinder is screwed to accommodate the lens holding cylinder, and the rear end surface of the lens holding cylinder is brought into contact with the front end surface of the large-diameter cylindrical portion of the main body and is joined and fixed to the main body by the connecting member An observation device comprising: a tubular body. 2. The observation apparatus according to claim 1, wherein the illumination optical system has one end connected to a light source and the other end arranged annularly along the inner peripheral surface of the large-diameter cylindrical portion of the main body. It consists of a light-emitting side optical fiber facing the front end surface of the large-diameter cylindrical portion, and an exit-side light guide body annularly arranged in the focus adjusting cylinder body, each end surface of which faces the end surface of the focus adjusting cylinder body. An observation apparatus characterized in that the light guide and at least the tip of the optical fiber are arranged coaxially with the image transmission means and the objective lens.