JPS59129820A - Endoscope photographing device - Google Patents

Abstract

PURPOSE:To prevent effectively a fact that moire fringes are generated on a photographed image by constituting a titled device so that influence caused by an array of a fiber can be eliminated, by using a double refraction element. CONSTITUTION:A double refraction element 19 selects the thickness of a plate surface to a suitable value in accordance with the size of a double refraction, and also rotates the plate surface, by which, for instance, an optical image O of a fiber 18A, which is formed on the film surface by an ordinary ray, and an optical image E of the fiber 18A, which is formed by an abnormal ray are shifted to about a radius of the fiber 18A. Also, to the part where an image of a dark part which is not the fiber 18A by the abnormal ray is made to coincide and fixed. In this way, the difference in contrast of light and darkness between a bright image and an image of a dark part of the part of the fiber 18A is eliminated, and even if a structure such as stripes, etc. exists in the film side, moire fringes are scarcely generated.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention is an endoscope that can be attached to an endoscope having an image guide formed by bundling fibers to prevent the occurrence of moiré fringes and enable clear imaging. ? l! This invention relates to a mirror photographing device.

[Technical background of the invention and its problems] In recent years, by inserting an elongated insertion part into a body cavity, internal organs, etc. in the body cavity can be observed, and if necessary, treatment with forceps etc. inserted through a channel for a treatment instrument has become popular. 2. Description of the Related Art Medical endoscopes are widely used, which can collect in-vivo tissues and diagnose affected areas in detail. Also, in the industrial field, boilers.

Endoscopes are also used for maintenance purposes, such as observing the condition inside pipes of chemical plants and the like, or collecting and inspecting deposits on the pipe interior surface.

The above-mentioned endoscopes include flexible endoscopes that have a flexible insertion section and a bendable structure, and rigid endoscopes that have a rigid insertion section that is approximately linear.

These endoscopes include an illumination optical system that transmits illumination light supplied to the proximal side when the insertion section is inserted and emits the illumination light from the distal end of the insertion section to the object side, and the illumination optical system. An observation optical system is provided that can form an image of the object illuminated by the camera and observe it from behind the eyepiece on the hand side via an image transmission means (image guide).

The above flexible endoscope generally uses a fiber bundle in which flexible (for example, a circular cross section and a diameter of about 10 microns) ultra-thin fibers are arranged in a stacked shape as an image guide. When stacked in bales, each fiber has a circular cross section, so there is a portion of each fiber that is not filled with fiber and transmits light, and a small gap that is not filled with fiber (this is where most of the light passes through). Since there is no transmission, it becomes a dark area, and each end is fixed with an adhesive such as acid solute glass.) are formed in a regular array, but this dark area is small enough to be easily observed. is almost never a problem. Since the insertion section has a sufficiently flexible fiber bundle inserted through it, there is no need to provide an insertion hole in the abdominal wall as in the case of general rigid endoscopes, and the insertion section can be inserted into the oral cavity or other places. It can be directly inserted into the body cavity via a curved path to the target site for observation.

When a camera as a photographing device is attached to the eyepiece of the above-mentioned flexible endoscope and an optical image of the target area (subject) is formed on the film loaded in the camera, the film is placed on a thin polyester base. ,green.

A filter in which striped filters of the three primary colors of blue are repeatedly arranged, for example, each stripe has a width of about 8 microns, and 394 sets of the three colors red, green, and blue are regularly arranged per 1 [cm]. Therefore, images are formed on the film due to the regularity of the arrangement between the fiber parts that transmit light and the minute dark areas where the fibers are not filled, and the regularity of the arrangement of the stripes of the film. Moiré fringes will occur in the optical image of the subject being photographed.

The manner in which such moiré fringes occur depends on the arrangement of the image guide formed by the fiber bundle and the stripes on the film, that is, the relative angular position with respect to the optical axis. occurs strongly, but less strongly or not at all at other angles. Therefore, if the relative angle between the image guide and the camera as a photographing device is fixed at an angle that does not cause moire fringes, moire fringes will not appear in the photographed image.

However, when actually using an endoscope, the angular position of the endoscope with respect to the operator is not constant; for example, the operator operates the operating section, bending operating section, treatment instrument insertion section, etc. provided on the endoscope. Since the camera often gets in the way when doing so, and the position of the camera to observe the 7 Aida changes variously, it is necessary to attach the camera so that it can rotate freely relative to the endoscope. Therefore, the relative angular position between the camera and the endoscope is arbitrary, and morea fringes occur in the photographed image.

In this case, the operator observing through the finder does not directly observe the image formed on the film stripe, but rather the image is reflected by the return mirror on the endoscope side (that is, in front) of the film. An image formed at a position that is optically conjugate with the position (this position does not have an array such as a stripe) is observed. Therefore, it is not possible to observe the moire fringes themselves and their intensity, so even if you take a picture with the target area clearly captured through the viewfinder, moire fringes may appear in the photographed image and the target area may become unclear. there were. For this reason, the value of the image as a diagnostic material is lost, making it impossible to make a correct diagnosis, or requiring the image to be taken again, which imposes a large burden or pain on the operator and the patient.

The effect of the moire fringes mentioned above cannot be known until after the film has been developed, so the operator has to check each frame individually to know whether the shot is sufficient or not, which is extremely inconvenient. there were.

[Purpose of the Invention] The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide an endoscopic photographing device that can effectively prevent the occurrence of moire fringes on a film even when photographing. shall be.

[Summary of the Invention] The present invention provides a birefringent element at an appropriate location between the proximal end surface of an image guide formed by a fiber bundle and the imaging position where a film, etc. is placed, and By superimposing images that are shifted by the radius of the fiber, the (bright) image that passes through the center of the fiber overlaps the dark image that cannot be filled with the fiber, and the The structure is such that the influence of the arrangement is substantially eliminated, and even if a film having an arrangement such as a stripe structure is used, the occurrence of moiré fringes can be effectively eliminated.

[Embodiments of the invention] Hereinafter, the present invention will be specifically explained with reference to the drawings.

Figure 1 shows the appearance of one embodiment of the present invention, and Figure 2 shows the main parts of the first embodiment, including the vicinity of the eyepiece of a flexible endoscope and the optical system of the camera attached to the eyepiece. 3 shows the exit end of the fiber imaged on the film plane of FIG. 2.

As shown in Figure 1, flexible endoscope (fiberscope) 1
consists of an elongated and flexible insertion section 2, a large-diameter operation section 3 connected to the rear end of the insertion section 2, and an eyepiece section 4 formed at the rear end of the operation section 3. , extending to the outside from the side of the operation unit 3;
It is comprised of a flexible universal cord 5 attached with a connector that can be attached to a light source device (not shown).

In the insertion section 2, a distal end component section 6 in which an objective optical system and the like are accommodated, and a curved section 7 are successively arranged from the distal end side,
By rotating a bending operation knob 8 formed on the operating section 3, the bending section 7 can be bent left and right or up and down.

A light-guide fiber for transmitting illumination light is inserted into the universal cord 5, and the light-guide fiber is bent by the operating section 3 and further inserted into the insertion section 2, and is then inserted into the objective optical system in the distal end component 6. It is configured to emit illumination light in a viewing direction that allows observation.

In addition, the operation section 3 is formed with a treatment instrument insertion section 9 such as forceps, and if necessary, a treatment instrument can be inserted through the treatment instrument insertion section 9 to collect tissue from the affected area and perform treatment such as diagnosis. It is now possible to do so.

On the other hand, the camera 11 as a photographing device is provided with a cylindrical portion 12 on the front end side of the camera body 13, which is formed with a mount that can be detachably attached to a mount provided at the rear end of the eyepiece section 4.

As shown in FIG. 2, a lens 14 is housed inside the cylindrical portion 12 forming the mount (in FIG. 2, a single lens including the eyepiece in the eyepiece 4 is shown).

), the surface of the loaded film 15 faces the imaging position where the image is formed by the lens 14. This film 1
5, red, green, and blue stripe filters 15R, 15G, and 15B are formed on a polyester base 15A, and silver halide grains 15C of an emulsion layer are formed above (behind) them.

The camera body 13 further includes a viewfinder 16.
(see Figure 1) are formed, and the lens 14 and film 15
The incident light is (usually) reflected by a return mirror (not shown) disposed between the film 15 and an optical image of the subject formed at a position optically conjugate with the imaging position where the film 15 surface is located. This return mirror is rotated and retracted in response to a photographing operation, and the light passing through the lens 14 is configured to form an image on the surface of the film 15.

The camera main body 13 is configured to be able to rotate with respect to the cylindrical portion 12 in a rotation plane 17 shown in FIG.

By the way, the image guide 1 has an optical image of the subject formed on its distal end surface by the objective optical system on the distal end side of the insertion section 2.
8 is formed by stacking fibers 18A having a diameter of, for example, 12 microns in a bale, and has an overall circular cross section having a diameter of about 2.4 mm. Such an image guide 18 is extended from the rigid tip portion 6 to the curved portion 7, and the insertion portion 2 and the operation portion 3 behind it to the eyepiece portion 4, and the optical image formed on the tip surface is The rear end surface of the eyepiece 4, that is, the exit end 18B as shown in FIG. 2 is provided with a crystal.

A birefringent element 19, which is formed by cutting out an optically birefringent element such as calcite into a plate shape, is mounted with an opening window and is fixed with a metal fitting 20 or the like.

The birefringent element 19 has optical anisotropy in its refractive index due to its crystal structure, and when a light beam is incident perpendicularly to the plate surface cut out so that the main axis of the crystal is not perpendicular to the plate surface, ' It separates into a ray called an ordinary ray that travels straight in that direction, and an extraordinary ray that travels in a curved direction, and both rays have the characteristic of becoming parallel to each other after passing through the crystal.

The birefringence element 19 has an optical image O of the fiber 18A formed on the surface of the film 15 by ordinary rays, and an optical image O of the fiber 18A formed by extraordinary rays, as shown according to the magnitude of birefringence. (shown by a broken line) is shifted by the radius of the fiber 18A, and the center of the optical image E of the fiber 18A due to the extraordinary ray is placed at the location where the dark area (of the fiber 18A) that is not the fiber 18A is formed by the ordinary ray. Fix it so that it matches.

By doing this, the difference in brightness and darkness between the bright image of the portion of the fiber 18A and the image of the dark area (mostly) not filled with the fiber 18A is substantially eliminated. One of the features of this embodiment is that even if there is a structure such as a stripe on the film 15 side, a means is formed in which moiré fringes hardly occur.

According to one embodiment of the present invention configured as described above, when observing from the eyepiece section 4 of the flexible endoscope 1 to which the birefringent element 19 is attached, the birefringent element 19 causes the observation to be slightly shifted. However, since the amount of deviation is sufficiently small, it does not pose a problem in practice.

On the other hand, when the camera 11 as a photographing device is attached to take a photograph, the optical image formed on the surface of the film 15 via the birefringent element 19 is bright as the light from each fiber 18A is transmitted, as described above. The difference in contrast is almost eliminated by the double images of the ordinary and extraordinary rays in the (almost) dark area where the fibers 18A are not filled, and the regularity of the fiber 18 arrangement. The occurrence of moiré fringes, which normally occurs due to the regularity of the arrangement of the stripes, etc. of the film 15, can be prevented almost regardless of the arrangement of the stripes, etc. of the film 15.

According to the first embodiment, when the camera 11+ is attached and observed from the viewfinder 16 (in this case, the camera body 13 can be rotated at any arbitrary angle with respect to the flexible endoscope 1 side) , if the optical image O due to the ordinary ray and the optical image E of the exit end 18B of the fiber 18A due to the extraordinary ray are observed as shown in FIG. This means that moiré fringes can be prevented even if the image is rotated.

Therefore, according to one embodiment of the present invention, the fiber 1 observed through the viewfinder 16 is
By checking whether the double image of the exit end 18B of 8A is set as described above, it is possible to avoid moire fringes on the photographed image even if the camera body 13 side is rotated at any angle when actually photographing. You can shoot with peace of mind knowing that this will not occur.

Moreover, as mentioned above, it is independent of the angle of the camera body part 13,
The birefringence element 19 must be integrally fixed to the exit end 18B of the fiber 18A because it is possible to know whether there is a possibility that moiré fringes will occur in the photographed image by observing through the viewfinder 16. Without,
It can also be configured to be detachable.

Furthermore, the position where the birefringent element 19 is fixedly or detachably mounted does not have to be in contact with the exit end 18B, but between the exit end 18B and the film 1.
5 and does not rotate together with the camera body 13.

In this case, if it is fixedly attached to the flexible endoscope 1 (of course rearward from the exit end 18B), the occurrence of moire fringes can be prevented with almost no relation to the state of the imaging device. Alternatively, it may be constructed so that it can be detachably attached to the mount portion of the eyepiece section 4. In this case, it is necessary to adjust
A scale may be provided on the outer periphery so that the angle can be easily set to an appropriate angle (without observing through the viewfinder 16), or a structure may be adopted that allows installation only at an appropriate angle. You can also.

Rather than attaching the birefringent element 19 to the flexible endoscope 1 side, it may be attached to the camera 11 side, for example, on the rotating surface 1.
Any part other than the mount part may be used as long as it is a part in front of 7. In this case, when it is mounted on the eyepiece, it is necessary to adjust the mounting angle to see if it is an appropriate angle.
Adjustment is easy if a scale or the like is provided on the outer periphery of the side mount to easily set the appropriate angle, and a click mechanism can be used to always set the appropriate angle.

If the birefringence element 19 is detachably attached to the flexible endoscope 1 side, it will be possible to remove it and observe an optical image without any deviation when observing with the naked eye.

Even when the birefringent element 19 is installed, if double images are considered to be bothersome, since the ordinary rays and extraordinary rays are polarized in directions in which their vibration planes are normally perpendicular to each other, If a polarizing plate is inserted, only one optical image can be observed. Also, slightly shifted images are superimposed, but the image caused by one (for example, an extraordinary ray) does not have to be a complete image, and the image caused by an extraordinary ray becomes an (incomplete) double image. Even if the image is correctly formed, it is sufficient that the bright image is superimposed on the dark part of the image.

Note that the present invention is not limited to imaging devices such as the camera 11 attached to the eyepiece of an endoscope that uses a fiber bundle as an image guide; It can be similarly applied to viewing devices with a guide formed thereon (including not only medical endoscopes but also industrial endoscopes).

). Further, as the above-mentioned photographing device, there is a television set in which a solid-state image sensor formed by arranging minute light receiving elements having a photoelectric conversion function such as a COD (charge coupled device) or a BBD (bucket brigade device) 1MOS image sensor is arranged at the imaging position. It can be similarly applied to cameras.

[Effects of the Invention] As described above, according to the present invention, the effect of fiber arrangement can be substantially eliminated by using a birefringent element, so that when a film loaded with a stripe or other arrangement is loaded. This has the advantage that even if a camera or the like is attached, it is possible to effectively eliminate moiré fringes that occur in a photographed image. Therefore, the operator can take pictures with peace of mind, and since there is no need to check each frame, the time required for taking pictures, etc. can be shortened, and the burden and pain on the operator and patient can be reduced.

[Brief explanation of the drawing]

1 to 3 relate to one embodiment of the present invention. FIG. 1 is a perspective view showing the external appearance of the first embodiment, and FIG. 2 is an explanatory diagram showing the vicinity of the exit end of an image guide equipped with a birefringent element. 1. FIG. 3 is an explanatory diagram showing an optical image of the exit end of the fiber formed on the film surface of FIG. 2. FIG. 1...Flexible endoscope @ 2...Insertion section 3...Operation section 4...Eyepiece section 6...Tip component 1
1...Camera 12...Cylinder part 13...Camera body part 14...Lens 15...Film 16...Viewfinder 18...Image guide 18A...Fiber 1
8B...Emission end 19...Birefringence element 20...
・Mounting with metal fittings

Claims (1)

[Claims] An endoscope has an image guide for image transmission formed by bundling fibers, and is detachably attached to the eyepiece of the endoscope, and a film having a filter structure such as a stripe shape is loaded at the imaging position. In an endoscope photographing device equipped with a camera such as a camera, or a photographing device such as a television camera in which a solid-state image sensor having a structure in which light-receiving elements having a photoelectric conversion function are arranged at an imaging position, A birefringent element is mounted either integrally or removably on the proximal exit end of the image guide, the mount part of the eyepiece, or the mount part of the imaging device, and depending on the arrangement of the fibers, images slightly shifted from each other are produced. An endoscope photographing device characterized in that an image is formed at the image forming position.