JPH10192221A - Video scope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a diaphragm diameter to be easily and securely changed, by equipping a thin plate to interrupt light with plural through holes with different diameters bent from the light axis direction to the lens face direction slidably in the longitudinal direction and selectively moving the through holes of the thin plate. SOLUTION: On one end of an iris diaphragm shutter 7 comprising a thin plate made of black metal or resin to interrupt light with a large through hole 7a and a small through hole 7b, a lever hole 7c to hold a lever 8 for elide sliding is equipped. A shutter cover 9 fixed on a holder 5 is formed in almost L-shapes on the objective side of an objective lens rectangularly crossing the light axis and the longitudinal direction side of the holder 5 in parallel with the light axis direction. On the shutter cover 9, a sliding groove 9a is equipped in the inside, an opening 9b on the light axis center, and a notch 9c for sliding in the longitudinal direction side, and the shutter 7 is placed along the sliding groove 9a and a displacing mechanism for sliding a CCD unit 4 onto the other end of the lever 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a videoscope having a built-in image pickup device such as a CCD, and more particularly to a variable image pickup magnification used by a doctor in dentistry, oral surgery and the like for photographing a patient's face and affected area. Dental scope.

[0002]

2. Description of the Related Art In recent years, a video scope using a CCD is used for medical treatment of an affected part in the oral cavity in dentistry and oral surgery. In such an apparatus, Japanese Patent Application Laid-Open No. 4-17643 is disclosed.
No. 6, the objective lens replacement unit is provided,
In some cases, the magnification of imaging can be changed. Further, as disclosed in Japanese Patent Application Laid-Open No. 4-283715, there is an apparatus in which an aperture blade is rotated to change an aperture diameter.

[0003]

In a videoscope for performing such local imaging such as observation of an affected part and imaging of a patient's face, it is required to change the imaging magnification in accordance with the size of the subject. In addition, since the operation at this time can be performed easily and quickly and is inserted into the oral cavity, a small-diameter and small-sized one is required.

However, in the conventional technique disclosed in Japanese Patent Application Laid-Open No. 4-176436, it is necessary to replace the corresponding lens when changing the magnification, which is cumbersome and requires extra time.

[0005] For these reasons, a method has recently been used in which the distance between the objective lens and the image pickup device is changed without replacing the lens. However, the focusing conditions are different between the case where the observation region is close and the case where the observation region is far, and when the region to be observed is far, the depth of field is wide and easy to focus, but when the region to be observed is close, the depth of field is small. Is too narrow to focus. Therefore, when the region to be observed is far, the aperture diameter is set to the standard state, and when the region to be observed is close, it is necessary to change the aperture diameter so as to reduce the aperture diameter and increase the depth.

In the prior art disclosed in Japanese Patent Application Laid-Open No. 4-283715, the rotation of the diaphragm blades for varying the diaphragm diameter is performed in a plane perpendicular to the optical axis, and further, a component such as an operating electromagnet is used. Since space is required, the leading end becomes large, and miniaturization cannot be achieved. There is also a method of continuously changing the aperture diameter by rotating a plurality of aperture blades, but since a large number of blades are required, the number of parts is large,
Even if simplified, two or three blades are required. Two
An iris diaphragm formed by three blades has an elliptical or triangular diameter, and it is difficult to obtain a highly accurate true circle effective diameter when a small diaphragm is used. In addition, continuous adjustment is difficult to quickly adjust the focus and is difficult to handle.

SUMMARY OF THE INVENTION In view of the foregoing, it is an object of the present invention to provide a video scope which is small in diameter, easy to miniaturize, and can easily and reliably change the aperture diameter.

[0008]

SUMMARY OF THE INVENTION In order to solve this problem, the present invention relates to a videoscope provided with an image pickup means having an objective lens and an iris diaphragm. A thin plate that blocks light is bent from the optical axis direction of the objective lens in the lens surface direction and provided so as to be slidable in the longitudinal direction, and by selectively moving the through-hole of the thin plate to the iris diaphragm position of the imaging means. , Which can be selectively changed to a preset iris diaphragm diameter.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

(Embodiment 1) FIG. 1 is a cross-sectional view of a distal end portion of a videoscope, 1 is an entrance portion, 2 is a prism mirror for side view, 3 is an objective lens, and one It consists of a single lens having a spherical surface or one cemented lens. Reference numeral 4 denotes a CCD unit. Reference numeral 5 denotes a holder for fixing the objective lens 3 and slidably holding the CCD unit 4. A sliding portion 6 is fixed to the CCD unit 4, and a displacement mechanism (not shown) such as a cam or a motor is connected to the other end of the sliding portion 6.

Reference numeral 7 denotes an iris diaphragm shutter having a large diameter through hole 7a and a small diameter through hole 7b and made of a thin plate, such as black metal or black resin, which blocks light, and has a lever 8 for sliding sliding at one end. A lever hole 7c is provided. In the present embodiment, SUS304 which has been subjected to black fermite treatment is used. The thickness was set to 0.04 mm. It should be noted that the thinner the shutter 7 is, the better the slidability is. On the contrary, if the shutter 7 is too thick, the shutter 7 is too hard to move smoothly.
Those having a diameter of 0.1 mm or less are preferable. The light transmissions 7a, 7b and 7c were formed by etching.

Further, a PET resin or the like may be formed in a thin film as the light-shielding plate 7, black may be applied, and light-shielding properties may be provided.

Reference numeral 9 denotes a shutter cover fixed to the holder 5, and has a substantially L-shaped shutter cover on the object side of the objective lens 3 perpendicular to the optical axis and on the longitudinal direction side of the holder 5 parallel to the optical axis direction. Formed. As shown in FIG. 2, the shutter cover 9 has a sliding groove 9a inside, an opening 9b at the center of the optical axis, and a notch 9c for sliding the lever 8 in the longitudinal direction. It is interposed along the groove 9a. The other end of the lever 8 is connected to the C
A displacement mechanism for sliding the CD unit 4 is connected in another system.

In the image pickup system, a prism mirror 2, a shutter 7, an objective lens 3, and a CCD unit 4 are arranged in this order from the tip of the entrance 1.

For example, when the photographing mode is the face, the large-diameter through hole 7a of the shutter 7 is located at the center of the optical axis of the objective lens 3, and the CCD unit 4 is located at an optimum distance from the objective lens 3. Next, when the imaging mode is set to the intraoral state, the displacement mechanism is operated by operating a switch (not shown). The shutter 7 slides along the sliding groove 9a of the shutter cover 9 by the movement of the lever 8 transmitted from a displacement mechanism, and the small-diameter through hole 7b is located at the center of the optical axis of the objective lens 3. Stop by the way. The CCD unit 4 is moved to an optimal distance from the objective lens 3 and stopped by the movement of the sliding portion 6 transmitted from the displacement mechanism.

Since the illumination can be performed by a known technique, the details are omitted. As described above, the diameter of the iris diaphragm can be selectively changed simply by sliding and sliding one thin plate in a substantially L-shape, and the configuration can be made space-saving.

Also, a predetermined iris diaphragm diameter is formed, and the required effective diameter can be obtained with a perfect circle with high accuracy. This is particularly effective for realizing a small diaphragm when obtaining the depth of field. is there.

Although it is difficult to adjust the optical axes and the distance between the lenses of the iris diaphragm provided in the set lens, it is slid along the objective side of one objective lens 3. Thus, assembly adjustment can be easily performed.

(Embodiment 2) In FIG. 3, reference numeral 27 denotes an iris diaphragm shutter having a plurality of through holes 27a having different diameters, and a lever hole 27c for holding a lever 28 for transmitting a displacement is provided at one or both ends. The shutter 27
Are substantially U-shaped on the object side of the objective lens 3 orthogonal to the optical axis and on both sides in the longitudinal direction of the holder 5 parallel to the optical axis direction.
It is interposed in the shape of a letter. Although the shutter cover is not shown,
Similarly, it is formed in a substantially U shape, and has a sliding groove, an opening, and a notch for sliding the lever 28 at one or both ends.

The operation of the displacement mechanism by the switch operation is transmitted from the lever 28, and the shutter 27 stops when a through hole suitable for the photographing mode is located at the center of the optical axis.

As described above, the diameter of the iris diaphragm can be selectively changed only by sliding one thin plate in a substantially U-shape, and both ends of the sliding direction are parallel to the optical axis direction. Therefore, the diameter of the distal end portion can be reduced and the size can be easily reduced. Further, since a longer thin plate can be used, the types of through holes can be increased.

Note that the bent shape may be a shape such as a substantially S shape, and is not limited to a substantially L shape or a substantially U shape.

[0023]

As described above, according to the present invention, the selection of the iris diaphragm diameter can be easily and reliably performed by sliding the slide of one thin plate, and the diameter and the size can be reduced. Good video scope can be provided.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a videoscope according to an embodiment of the present invention.

FIG. 2 is a perspective view of components of a videoscope according to one embodiment of the present invention.

FIG. 3 is a perspective view of components of a videoscope according to one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Entry part 3 Objective lens 4 CCD unit 5 Holder 7 Iris diaphragm shutter 9 Shutter cover

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hirofumi Yamakita 1006 Kazuma Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (4)

[Claims] In a videoscope provided with an image pickup means having an objective lens and an iris diaphragm, a single light-blocking thin plate having a plurality of through-holes having different diameters in a longitudinal direction is provided from the optical axis direction of the objective lens. It is provided to be bent in the lens surface direction and slidable in the longitudinal direction, and by selectively moving the through-hole of the thin plate to the iris diaphragm position of the imaging means, the iris diaphragm diameter can be selectively changed to a preset iris diaphragm diameter. A video scope characterized by the following: 2. The objective lens is one single lens or one objective lens.
2. The video according to claim 1, wherein one thin plate fixed as a plurality of bonded lenses and having a plurality of through holes having different diameters is provided so as to be slidable substantially along the lens surface of the objective lens. scope. 3. A videoscope in which an image pickup means having an objective lens, an iris diaphragm and an image pickup device is disposed near the distal end, a slidable thin plate serving as an iris diaphragm, a fixed objective lens, and a light source. 2. The video scope according to claim 1, further comprising: an imaging element movable in an axial direction. 4. A thin plate having a plurality of through holes is provided so as to be bent and slid in a direction from the optical axis direction of the objective lens to the lens surface direction and further in the optical axis direction. Video scope as described.