JPH10211162A - Visual field direction selection type endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure the visual fields of two directions by one endoscope and to improve medical examination efficiency by dividing an optical axis in the two directions in an objective optical system, securing the visual fields of the two directions, disposing a linear polarizing plate on the divided respective optical axes and disposing the linear polarizing plate capable of selecting a polarizing direction in an eyepiece optical system. SOLUTION: The optical axis X of the objective optical system B is divided into the two optical axes X1 and X2 by a beam splitter 3, one optical axis X1 is directed to the axial direction of a viewing tube body 1, the other optical axis X2 is directed to the direction orthogonally crossing the axis of the viewing tube body 1 and concave lenses 5 and 7 and the linear polarizing plates 4 and 6 are disposed to the respective ones in an order from an object side. At the time, the polarizing directions of the respective linear polarizing plates 4 and 6 are set so as to be mutually orthogonal polarized light on the optical axis X before division. Also, in the eyepiece optical system A, the linear polarizing plate 9 is disposed behind an eyepiece 8, the polarizing direction of the linear polarizing plate 9 is changed to the orthogonal direction of the polarizing direction of the linear polarizing plate 4 or 6 and thus, one polarized light image is interrupted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope, and more particularly, to a rigid endoscope capable of selecting a viewing direction.

[0002]

2. Description of the Related Art Normally, the field of view of a rigid endoscope is fixed in an arbitrary direction at a certain viewing angle with respect to the optical axis. There are various directions, for example, direct view, front perspective, side view, etc., and practical use has been achieved. Among them, a mirror is arranged in the objective optical system at the distal end of the visual tube body, and the optical axis is bent by reflection to secure an arbitrary visual field direction in the front perspective and side view.

[0003]

As described above, in the prior art endoscope, the viewing direction is fixed in advance.
Therefore, in order to observe a different direction, an operation of rotating or tilting the endoscope is necessary, and in some cases, there is a possibility that the organ to be observed may be damaged. In addition, when this is not possible, there is an inconvenience in that a plurality of types of endoscopes having different viewing directions according to the observation target and the range must be prepared.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to provide an endoscope capable of selecting a viewing direction. That is, in the endoscope of the present invention, the optical axis is divided into two directions in the objective optical system to secure a visual field in two directions, and a linear polarizer is placed on each of the divided optical axes at the optical axis before the division. It is characterized by being arranged so as to be orthogonally polarized light, and a linear polarizing plate capable of selecting a polarization direction is arranged in the eyepiece optical system.

Therefore, according to the endoscope of the present invention, observation light beams of images in two directions are simultaneously incident on the eyepiece optical system, but the polarization direction of the linear polarizing plate of the eyepiece optical system is changed by the objective optical system. By making the polarization direction orthogonal to the polarization direction of one of the linear polarizing plates, this polarization image is cut off by the orthogonal polarization effect, and an effect is produced that allows only the remaining polarization image to be observed.

[0006]

Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a view showing an optical system of an endoscope according to the present invention. In the figure, reference numeral 1 denotes a visual tube, A denotes an eyepiece optical system, and B denotes an objective optical system. In the figure, reference numeral 3 denotes a beam splitter (here, a prism is used), and the optical axis X of the objective optical system B is changed by the beam splitter 3 into two optical axes X1 and X2 in different directions with respect to the object side. X2.

The optical axis X1 is directed in the axial direction of the visual tube 1, and the concave lens 5, the linear polarizing plate 4
Is arranged. On the other hand, the optical axis X2 is directed in a direction orthogonal to the axis of the visual tube 1, and a concave lens 7 and a linear polarizing plate 6 are arranged in this order from the object side. In this case, the polarization direction of the linear polarizer 4 along the optical axis X1 (the symbol P1 in the figure conceptually illustrates this polarization direction) and the polarization direction of the linear polarizer 6 along the optical axis X2 (the symbol P2 in the figure is this direction). The polarization directions conceptually illustrated) are set so as to be orthogonal to each other on the optical axis X before division.

Accordingly, the observation light beam on the optical axis X1 passes through the beam splitter 3, enters the imaging lens 2 located on the optical axis X, and passes through a relay lens (not shown) to the eyepiece of the eyepiece optical system A. 8 is incident. The observation light beam on the optical axis X2 is deflected by the beam splitter 3 and is incident on the imaging lens 2 on the optical axis X, and is incident on the eyepiece 8 of the eyepiece optical system A via a relay lens (not shown). Is done.

In the above case, the observation light beams of the images in the two directions of the optical axes X1 and X2 are incident on the eyepiece lens 8 at the same time as it is, and the observer sees these images simultaneously. In the eyepiece optical system A, the polarization direction of the linear polarizer 9 disposed behind the eyepiece lens 8 is changed to the polarization direction of the linear polarizer 4 or 6 of the objective optical system B (indicated by P3 and P4 in FIG. By changing the direction to be orthogonal to that conceptually illustrated), this polarized image is blocked by the orthogonal polarization action.

In this case, a mechanism for changing the polarization direction of the linear polarizing plate 9 is required. Here, embodiments of two kinds of mechanisms will be disclosed. 2 to 4 show a first embodiment of this mechanism. Here, the direction of polarization is changed by rotating the linear polarizing plate 9 about the optical axis X. Specifically, the polarizing plate holder 10 holding the linear polarizing plate 9 is attached to the viewing tube 1. It is provided at the end so that it can rotate freely.

The holder 10 has a common center at the optical axis X.
A pair of arcuate guide grooves 12, 12 provided on the front and back are provided to penetrate the guide groove, and a pair of headed guide shafts 15, 15 to be fixed to the end of the visual tube body 1 by screwing in the guide grooves. By being slidably inserted in the direction, it is rotatably disposed within a limited range (here, 90 degrees) with respect to the visual tube 1.
On the other hand, reference numeral 14 in the drawing denotes a holding plate for realizing the above-mentioned holder 10 to prevent the holder 10 from slipping off and to perform a click action, and is formed of a material having spring properties into a plate shape having an eyepiece window 14H at the center. Then, before inserting the guide shafts 15, 15 into the pair of guide grooves 12, 12 of the holder 10,
This holding plate 1 is used as a stopper for the flange-shaped head of the guide shaft.
4 is first inserted through the holding plate 14 and the sight tube 1
The holder 10 is sandwiched between the end faces of the holder 10.

The back surface of the holding plate 14 is the holder 10
A plurality of countersunk recesses 13 (e.g., four every 90 degrees) at equal pitches at a location one step lower around the convex portion 11 on the surface of the holder 10.
A plurality of pins 16 each having a hemispherical tip at the position corresponding to the depression 13 on the back surface of the holding plate 14, and dropping each pin 16 into each depression 13. Means for stopping the holder 10 to be clicked at a predetermined position (specifically, a position where the polarization direction of the linear polarizing plate 9 is orthogonal to the polarization direction of either the linear polarizing plate 4 or 6 of the objective optical system B). I have.

FIGS. 5 to 7 show a second embodiment of this mechanism. Here, one of a pair of linear polarizing plates 9A and 9B having different polarization directions can be selectively arranged on the eyepiece.
A slide plate 23 holding A and 9B is slidably provided at the end of the visual tube 1.

The slide plate 23 has a downward U-shape in cross section with a pair of side plates hanging down from both ends. On the other hand, a pair of parallel cutout flat portions is formed on the peripheral side of the end of the viewing tube 1. The flat portions 20 and 20 are sandwiched between a pair of side plates of the slide plate 23. And
Guided grooves 24, 24 provided along the entire length of the pair of side plates of the slide plate 23 allow the headed guide shafts 15, 15, and 26 to be screwed to the flat portions 20, 20 to be slidable in the groove direction. By being inserted, the slide plate 23 is slidable in a direction orthogonal to the optical axis X of the visual tube 1. In this case, the guide shaft 26 presses the slide plate 23 by interposing a wave washer (not shown) between the flange-shaped head and the side plate of the slide plate 23, and slides so that the position does not change unnecessarily. Giving resistance. Incidentally, reference numeral 2 in the figure
Reference numeral 5 denotes a knob serving as a key for sliding the slide plate 23 in this case.

In this embodiment, the linear polarizing plate 9A is the linear polarizing plate 4 of the objective optical system B, and the linear polarizing plate 9B is the slide plate 23 so that the polarization direction is orthogonal to the linear polarizing plate 6 of the objective optical system B. By selectively sliding these linear polarizers in the eyepiece window 1H at the end of the visual tube 1 by sliding the slide plate 23, any polarized image is blocked.

[0016]

According to the present invention having the above configuration,
Since a single endoscope can secure a visual field in two directions, the inconvenience of preparing a plurality of types of endoscopes having different visual field directions according to the observation target and the range is eliminated.

Further, since the visual field can be switched with one touch by switching the linear polarizer of the eyepiece, the visual field can be switched while observing, and in this case, there is no need to rotate or tilt the endoscope. Therefore, a safe consultation is realized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an example of an optical system of an endoscope according to the present invention.

FIG. 2 is a perspective view of the first embodiment of the eyepiece;

FIG. 3 is a front view of the first embodiment of the eyepiece;

FIG. 4 is a partially cutaway side view of the first embodiment of the eyepiece;

FIG. 5 is a perspective view of a second embodiment of the eyepiece unit;

FIG. 6 is a front view of the second embodiment of the eyepiece;

FIG. 7 is a partially cutaway side view of the second embodiment of the eyepiece;

[Explanation of symbols]

 A eyepiece optical system B objective optical system X optical axis X1 (divided) optical axis X2 (divided) optical axis 2 imaging lens 3 beam splitter 4 linear polarizer 6 linear polarizer 9 linear polarizer

Claims (4)

[Claims] In an objective optical system, an optical axis is divided into two directions to secure a field of view in two directions, and a linear polarizing plate is orthogonally polarized on each of the divided optical axes at an optical axis before division. A viewing direction selecting endoscope, wherein a linear polarizing plate capable of selecting a polarizing direction is provided in the eyepiece optical system. 2. An endoscope according to claim 1, wherein an optical axis is divided into two directions by disposing a beam splitter on the object side of the imaging lens. 3. A linear polarizing plate is provided on the eyepiece so as to be rotatable about the optical axis, so that the polarization direction of the linear polarizing plate can be matched with the polarization direction of each linear polarizing plate of the objective optical system. 3. A viewing direction selectable endoscope according to claim 1 or 2. 4. The visual field according to claim 1, wherein any one of a pair of linear polarizers corresponding to the polarization direction of each linear polarizer of the objective optical system can be selectively arranged on the eyepiece. Direction selectable endoscope.