JPS59137921A - Endoscope device - Google Patents

Abstract

PURPOSE:To prevent Moire stripes from appearing in a photographed image by deforcusing and forming an optical image formed on a recording medium surface during photography. CONSTITUTION:A barrel part 15 is mounted on the eyepiece part 4 of a soft endoscope 1 and a camera body 14 is mounted on the barrel part 15. When a release button is pressed, a strobe emits light and a mirror shutter 17 rotates back; and a monostable multivibrator 31 outputs pulses and a transistor(TR) 32 is turned on to supply a current to a coil 24. Then, a lens 16 is moved back along an optical axis against the energizing force of a spring as shown by an arrow A and light passed through the lens 16 is formed on the surface of a film 18 while defocused. In this case, the outward shape of each fiber 6A corresponding to a picture element is only out of focus, so even when the image is formed on a film 18 having stripped filter structure, no Moire appears. Therefore, an operator takes a photograph while observing a subject clearly through a finder, realizing photography without Moire stripes all the time.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention is an endoscope having an image guide formed by bundling fibers, and a photographing device loaded with a recording medium such as a film arranged in a color stripe pattern. The present invention relates to an endoscope device that can effectively prevent the occurrence of moiré fringes even when photographing with a camera.

[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 approximately 8 microns, and 394 sets of the three colors red, green, and blue are regularly arranged per 1 [cm]. Therefore, due to the regularity of the arrangement due to minute dark areas where the fiber is not filled between the part of the fiber that transmits light and the outer periphery of each fiber, and the regularity of the arrangement of the stripes of the film. Moiré fringes will occur in the optical image of the subject formed on the film.

The manner in which such moiré fringes occur depends on the arrangement of the image guide formed by the fiber bundle and the film stripe, that is, the relative angular position around the optical axis.
Moiré fringes occur strongly at certain angles, 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 lfl image.

However, when actually using an endoscope, there is a need for the operator to understand what is inside the endoscope. The angular position of the II mirror is not constant, and for example, the camera often gets in the way when operating the operation section, bending operation section, treatment instrument insertion section, etc. provided on the endoscope, and the camera often gets in the way. Since the position at which the figu is observed changes variously, it is desirable that the camera can be attached to the endoscope so that it can rotate freely. In this case, the relative angular position between the camera and the endoscope is arbitrary, and morea fringes will occur in the captured 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 a return mirror on the endoscope side (that is, in front) of the film, and the image is reflected to the film's position. An image formed at a position that is optically conjugate with (this position does not have a stripe or the like arrangement) 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 moiré fringes mentioned above cannot be known until after the film is developed, so the operator has to check each section separately to know whether the image taken is sufficient, which is very inconvenient. Met.

[Object 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 endoscope device that can effectively prevent the occurrence of moire fringes on a recording medium such as a film when photographing. With the goal.

[Summary of the Invention] The present invention provides a transparent member such as a lens between the proximal end surface of an image guide formed of a fiber bundle and an imaging position where a film or the like is arranged, or a film or the like arranged at the imaging position. By forming a means to defocus and form an image by moving it in the optical axis direction during shooting, moiré fringes can be prevented even when shooting using a film having an array such as a stripe structure. It is configured to effectively eliminate the problem.

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

FIGS. 1 to 4 relate to a first embodiment of the present invention.
The figures show the main parts of the first embodiment of the present invention, which is composed of a flexible endoscope and a camera attached to the flexible endoscope, Fig. 2 shows the color stripe structure of the film, and Fig. 3 shows the structure of the color stripe of the film. 4 shows the structure of a driving means for moving the lens to defocus and form an image, and FIG. 4 shows a driver circuit for operating the driving means.

In these figures, within softness? ! The mirror 1 includes an elongated and flexible insertion section (not shown), a large-diameter operation section 3 connected to the rear end of the insertion section, and an eyepiece section formed at the rear end of the operation section 3. 4, and a flexible universal cord 5 that extends outside from the side of the operating section 3 and has a connector attached thereto that can be attached to a light source device (not shown).

Inside the insertion section, flexible fibers 6A are bundled in a stacked shape and transmit an optical image of the object formed on the distal end surface by an objective lens disposed on the distal end side to the proximal end surface. The formed image guide 6 is inserted, and a light guide 7 formed by bundling flexible fibers is also inserted, and this light guide 7 transmits the illumination light inside the light source device.
The light guide 7 is configured to emit light from the distal end surface of the light guide 7 to illuminate the object within a field of view that can be observed by the objective lens.

The image guide 6 is made by arranging and bundling each fiber 6A with a diameter of 12 microns in a stacked shape, for example, to form an image guide 6 having a diameter of 2.4 [u+] in the overall circular cross section, and the end surface on the proximal side. A beam splitter 8 formed by joining two prisms is disposed on the optical axis immediately behind 6B, and a part of the light is reflected by the joint surface of the beam splitter 8 and sent to a light receiving element for photometry. It is configured to be split into light that travels toward the eyepiece lens 9 side, and light that passes through most of the remaining light and travels toward the eyepiece lens 11 side that is disposed on the rear optical axis.

The amount of light received by the light receiving element 9 is converted into an electrical signal corresponding to the amount of light, and is input to the control circuit in the light source device via the cable 12, and the strobe light emission time in the light source device during photographing operation is photographed. The exposure amount can be automatically controlled to the appropriate amount.

A mount portion is formed on the outer periphery of the eyepiece portion 4, and a mount for a camera 13 as a photographing device can be attached to the mount portion.

This camera 13 is composed of a camera main body part 14 and a cylindrical part (camera adapter) 15 that can be detachably attached to the front surface of the camera main body part 14 and has the above-mentioned mount. Inside is for photographing (or imaging)
A lens 16 is disposed, and a mirror shutter 17 is disposed within the camera body 14 behind the lens 16, and a mirror shutter 17 is disposed at a predetermined image forming position within the camera body 14 where the image is formed by the lens 16. The cassette film 19 is loaded so that the film 18 side faces.

The light that has passed through the lenses 11 and 16 is reflected by the mirror shutter 17, and the operator can observe an optical image formed at a position that is optically conjugate with the image formation position. As shown,
The light that has rotated and retreated and passed through lenses 11 and 16 is transferred to film 18.
It is designed to reach the surface. (In FIG. 1, the mirror shutter 17 is shown schematically, and is actually disposed on the upper side of the page.) The film 18 loaded in the camera body 14 is
The back side of the film 1 is pressed by the pressure plate 20.
This is done so that the 8 sides are sufficiently flat.

As shown in an enlarged view in FIG. 2, the film 18 consists of an emulsion in which color filters of the three primary colors of red, green, and blue, indicated by symbols R, G, and B, are arranged in stripes, and behind them are emulsions containing silver halide grains. For example, when exposed to green light, the silver halide grains behind the green filter G are exposed, while the silver halide grains in the emulsion layer behind the red and blue filters R and B are not exposed. It looks like this.

As shown in FIG. 3, a frame 21 attached to the outer periphery of the lens 16 is accommodated in the cylindrical portion 15, and the movement of the frame 21 is regulated by a spring 22 via a connecting member such as a curved rod. The plunger 23 is connected to the plunger 23. The plunger 23 is composed of, for example, a movable iron piece connected to a connecting member, and a coil 24 wound around a hollow member that loosely fits around the outer shape of the movable iron piece.When an alternating current is supplied to the coil 24, , the movable iron piece is slightly displaced in a direction that resists the biasing force of the spring 22, for example, in the direction indicated by the arrow A, and at the same time, the lens 16 is displaced in the same direction A along the optical axis direction to form a bond on the film 18 surface. A driving means is formed to defocus the imaged (focused before displacement) optical image.

The degree of this defocus is sufficient to blur the outline of each fiber 6A that is imaged together with the subject, and thereby the contrast of the darkness between the portion of each fiber 6A and the dark part of its outer periphery is made uniform, Even if the optical image of the subject transmitted to the proximal end surface 6B of the image guide 6 is formed on the surface of the film 18 having a structure such as a stripe,
This is done so that no moire fringes are generated, or almost no moire fringes are recognized, with almost no deterioration in the quality of the optical image.

The driver circuit 26 that supplies current to the coil 24 in conjunction with the photographing operation is configured as shown in FIG. 4, for example.

That is, the output end of the release signal generation circuit 27, which is housed in the camera body 14 and generates a release signal in response to a shooting operation using the release button, etc., is connected to the input of the driver circuit 26 in the cylinder part 15 via contacts 28.28. connected to the end. This input end is connected to the input end of a mono multi vibrator (hereinafter abbreviated as mono multi) 31 which outputs a high level pulse signal for a certain period of time using the release signal as a tri signal. The output terminal of this monomulti 31 is connected to the base of an NPN type transistor 32 for driving.
When a high-level release signal is supplied to the base, sufficient current is supplied to the plunger coil 24 connected between the collector of this transistor 32 and the power supply terminal +,
The above-mentioned movable iron piece can be moved. In addition, the power supply end (2) is also connected to the power supply end so that power can be supplied to the monomulti 31. - The release signal transmitted to the cylindrical part 15 side via the contacts 28.28 is further transmitted to the flexible endoscope 1 side via the cable 34 in the cylindrical part 15 and the contacts 35.35. The signal is transmitted to the light source device side via the cable 36 in the endoscope 11, and the strobe is configured to emit light when the release signal is generated.

According to the first embodiment of the present invention configured as described above, the tube portion 15 is attached to the eyepiece portion 4 of the flexible endoscope t11, the camera body portion 14 is further attached to the tube portion 15, and the camera body portion 14
An optical image of a focused object formed at a position conjugate with the film 18 can be observed through the finder.

When a photographing operation such as pressing a release button is performed, a release signal is generated, the strobe in the light source device emits light, and the mirror shutter 17 is rotated and retracted.

At the same time, the monomulti 31 outputs a high-level pulse in response to the release signal, turns on the transistor 32, supplies current to the coil 24 of the plunger, and connects the movable iron piece and the lens 16 connected to the movable iron piece to the spring 22. It is moved backward along the optical axis as shown by arrow A against the urging force, and the light that passes through the lens 16 forms an image on the surface of the film 18 while being slightly defocused to the rear side. The degree of this defocus is determined by each fiber 6A corresponding to a pixel.
Since the outline of the optical image is only blurred, there is almost no loss in the quality of the optical image, and a stacked bale-like pattern does not appear, so even if the image is formed on the film 18 having a striped filter structure. This means that moire fringes will not appear. When the appropriate exposure amount is reached, the control circuit stops the strobe light emission and returns the monomulti 31 to its initial state in which it does not output high-level pulses. Along with this, the lens 16 is moved by the spring 22.
will be returned to its original position.

Therefore, if the operator performs the photographing operation while being able to clearly observe the subject through the finder, the operator can always take photographs without moiré fringes. Therefore, the operator does not need to check each frame one by one.
The required number of frames can be photographed quickly. Furthermore, since the time during which the flexible endoscope 1 is inserted and images are taken is shortened, the patient's pain is significantly reduced.

In the first embodiment described above, the lens 16 is moved backward (or forward) in conjunction with the photographing operation for defocusing, but the eyepiece 11 may also be moved.

FIG. 5 shows a second embodiment of the invention.

That is, a screen 41 is disposed at a position optically conjugate with the image formation position of the film 18 surface in the camera body 14, and the optical image formed on this screen 41 passes through a pentaprism 42. Observation can be made from behind the finder lens 43.

In this second embodiment, the film 1 at the imaging position is
The screen 41, which is disposed in a conjugate relationship with the eight planes, is disposed so as to be slightly shifted backward or forward along its optical axis direction.

In other words, when the mirror shutter 17 is rotated and retracted to form an optical image on the film 18 side while the optical image clearly formed on the screen 41 can be observed from behind the lens 43, the image guide 6 is placed on the proximal side of the image guide 6. It is configured so that the image is formed with a slight defocus to the extent that the pattern of each fiber 6A on the end face 6B and the dark part on its outer periphery is blurred. Other elements described in the first embodiment are given the same reference numerals.

With such a simple configuration, it is possible to observe the image in the best focused state, and if the photographing operation is performed in this state, it is possible to take a sufficiently clear photograph without moiré fringes.

In the second embodiment, the position of the screen 41 is slightly shifted to slightly shift the relationship between the conjugate positions (by moving the pressure plate 20 forward or backward on the side of the film 18 at the imaging position). However, a transparent plate such as a glass plate that changes the optical path length may be disposed in the optical path between the screen 41 and the mirror shutter 17, or a transparent plate such as a glass plate may be disposed in the optical path between the mirror shutter 17 and the film 18 surface. The conjugate relationship can be slightly shifted even if the optical path is placed between the two optical paths.

The above-mentioned conjugate relationship can be shifted when photographing using a driving means as in the first embodiment, or manually just before photographing. In this case, the optical image formed on the film 18 surface should be slightly defocused, and the pressure plate 20 may be moved. A transparent plate may be interposed in the optical path between the two, or the interposed transparent plate may be removed from the optical path.

In the second embodiment, instead of shifting the screen 41, the screen is arranged at a position conjugate to the image forming position by overlapping a transparent plate on the reflective surface of the mirror shutter 17 or applying transparent paint. The same function can be obtained by shifting the optical path length to 41 to be slightly larger.

Note that the present invention can be similarly applied to a case where a return mirror and a shutter are used instead of the mirror shutter 17.

As is clear from the above description, what is disposed at the imaging position is not limited to the recording medium such as the striped film 18, but also includes COD (charge coupled device), BB, etc.
D (bucket brigade device).

The present invention can be similarly applied to a photographing device such as a television camera equipped with a solid-state image sensor formed by arranging a large number of light receiving elements capable of photoelectric conversion such as a MOS image sensor. (In the above description, shifting the film 18 corresponds to shifting the solid-state image sensor surface.)

In the above description, the cylindrical portion 15 serving as the camera adapter may have a structure that can be attached to and detached from the camera body portion 14, or may be integral with the camera body portion 14.

Furthermore, the present invention can also be applied to a viewing mirror that is detachably attached to the eyepiece section 4 of the flexible endoscope 1.

In other words, when observing at the secondary eyepiece through a flexible image guide formed by bundling fibers, if Moiré fringes occur, the eyepiece 11 must be moved or the optical fibers formed on the distal end of the image guide must be moved. 1. Moiré fringes can be eliminated by defocusing by moving the lens.

Note that the present invention is applicable not only to the soft inner pit, a, but also to the image guide formed by bundling fibers.
It can also be applied to rigid endoscopes.

[Effects of the Invention] Since the optical image is formed so as to be defocused at least during photographing, it is possible to effectively prevent moire fringes from occurring in the photographed image. Therefore, the operator can quickly complete the imaging of the required number of frames, and the patient's pain is significantly reduced.

[Brief explanation of the drawing]

FIGS. 1 to 4 relate to a first embodiment of the present invention.
The figure is an explanatory diagram showing the main parts of the first embodiment, Fig. 2 is an explanatory diagram showing a striped film, Fig. 3 is a schematic perspective view showing the driving means, and Fig. 4 is a circuit diagram showing the driver circuit. , 5th
The figure is an explanatory diagram showing the main part of a second embodiment of the present invention. 1...Flexible endoscope 4...Eyepiece 6...
Image guide 6A...Fiber 6B...Hand side end surface 11...Eyepiece 13...Camera 14...Camera body 15...Cylinder part 16...
・Lens 17...Mirror shutter 18...Film 20
...Press plate 21...Frame 22...Spring 23.
... Plunger 24 ... Coil 26 ... Driver circuit 27 ... Release signal generation circuit 31 ... Mono multivibrator 32 ... Transistor 41 ... Screen 4
2...Pentaprism Figure 1 Figure 2 Figure 3 □ Figure 4 Figure 5

Claims (4)

[Claims] (1) An endoscope having an image guide formed by bundling fibers, which is detachably attached to the eyepiece of the endoscope,
It is equipped with a camera in which a film having a stripe-like arrangement is arranged at a predetermined imaging position, or a photographing device such as a television camera in which a solid-state image sensor formed by arranging light receiving elements is arranged in an imaging position. In the endoscope apparatus, means for moving a lens disposed between the optical path between the proximal end surface of the image guide and the imaging position, or means for varying the optical path length between the optical path, or At least by providing a means for shifting the conjugate relationship with a position that is optically conjugate to the image forming position during photographing operation, a means for defocusing and forming an image on the plane of the image forming position during photographing is formed. An endoscope device characterized by: (2) The endoscope apparatus according to claim 1, wherein the means for moving the lens is configured to be controlled in conjunction with a photographing operation. (3) The endoscope apparatus according to claim 2, wherein the means for moving the lens is formed by a plunger that moves a movable piece connected to the lens in response to a photographing operation. (4) The means for varying the optical path length is formed by interposing a transparent plate between the optical paths or by removing the interposed transparent plate from the optical path. The endoscope device according to item 1. (5) The means for shifting the conjugate relationship may be arranged between the optical path between a mirror shutter or return mirror interposed during observation and the conjugate position, or between the optical path between the mirror shutter or return mirror and the image forming position. Either a screen formed of a transparent plate inserted or removed between the two, or a screen disposed at the conjugate position, or a film disposed at the imaging position, is moved in the optical axis direction. The endoscope device according to claim 1, characterized in that it is formed by.