JPH0966020A - Endoscope device - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: By using a single lens as a diffusing lens, different light distribution is made for each of two branches of a light guide, and both when observing a lumen portion and when observing a plane portion. (EN) Provided is an endoscope device which can realize an optimal light distribution characteristic. A bundle of optical fiber strands having a numerical aperture NA1 is arranged at the center of the incident end of a light guide, and a bundle of optical fiber strands having a numerical aperture NA2 (NA1 <NA2) is arranged outside thereof. To place. Since the narrow-angle light distribution is obtained from the exit end of the bundle 36 of 81 and the wide-angle light distribution is obtained from the exit end of the bundle 37 of 82, the burdens on the narrow-angle diffusion lens 21 and the wide-angle diffusion lens 22 are small, respectively. It can be configured with a single lens. The high-brightness part detection circuit 69 detects the high-brightness part of the captured image and controls the light-shielding mechanism 46 to reduce the illuminance of the high-brightness part to facilitate observation and prevent halation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope apparatus for illuminating illumination light and observing the inside of a living body, and more particularly, it has improved light distribution characteristics of a light guide for guiding illumination light using an optical fiber. The present invention relates to an endoscope device.

[0002]

2. Description of the Related Art An endoscope apparatus has an endoscope scope body which has a distal end portion and a guiding center portion which are inserted into a lumen of a subject, and which is manually operated by an operator, and an endoscope scope body. And an endoscope processor device connected to the extending universal cord. The functions of the endoscopic device include
An observation system function for observing the lumen of the subject's upper respiratory tract, digestive tract, etc., and for collecting a biopsy sample from the observation target, removing foreign substances, and supplying air and water to the inside of the subject. There is a treatment system function.

The observation system function guides light from a light source provided in the endoscope processor device to the distal end of the endoscope by means of a light guide, and illuminates the region of interest of the subject with illumination light from the distal end. Then, it is realized by capturing an image of the subject by the image capturing means provided at the tip.

The function of the treatment system is to insert various treatment tools into the forceps holes provided in the main body of the endoscope and project the tip of the treatment tool into the inside of the subject from the opening of the forceps holes provided in the tip. Then, necessary treatment is performed. Further, the treatment of supplying air and water is performed by operating the air supply and water supply device provided in the endoscope processor device from the operation unit of the endoscope scope main body.

In general, the illumination in the function of the observation system is divided into two at the exit end of the light guide in order to reduce the diameter of the tip of the endoscope and to obtain a good illumination effect in various usage situations. Often, two lights are used.

As shown in FIG. 5, for illumination in the conventional endoscope apparatus 1, the light from the lamp 41 of the light source apparatus 4 is condensed by a condenser lens 44, and a universal mechanism is passed through a diaphragm mechanism 45 for adjusting the light quantity. It is guided from the connector portion 31 of the cord 30 to the incident end which is one end of the light guide 90. The light guide 90 is configured by bundling a large number of optical fiber strands having the same numerical aperture, and the operation unit 29 of the endoscope scope main body 2 serves as the light guide 90.
One is a branch 91 for small-diameter, narrow-angle illumination, and the other is a branch 92 for large-diameter, wide-angle illumination. A diffusion lens 93 is provided from each emission end to the distal end portion 27 of the endoscope. , 94, and is radiated and radiated from the front surface of the tip of the endoscope to illuminate the subject.

FIG. 6 shows the light distribution characteristics of the endoscope having the conventional two-branch light guide as the illuminance on a plane perpendicular to the endoscope optical axis. As is clear from FIG. 6, one of the two branches has a narrow-angle light distribution characteristic, and the other has a wide-angle light distribution characteristic.
The light is distributed so that the illuminance in the central part is high and the illuminance in the peripheral part is low. This is because when observing a luminal part such as the esophagus, it is necessary to have a light distribution characteristic with increased illuminance in the central part in order to illuminate deep inside the luminal part, and when observing a flat part such as the stomach wall. This is because a wide and uniform light distribution characteristic is required, and the light distribution characteristic is a compromise between both.

[0008]

However, since the light distribution characteristics of the above-mentioned conventional endoscope scope are eclectic characteristics when observing the lumen portion and when observing the flat surface portion, the lumen portion. When observing, the illuminance is insufficient at the center of the screen, and when observing the flat surface, the illuminance becomes excessive at the center of the screen, which may make it difficult to observe the subject or cause halation. There was a problem.

Further, since the above-mentioned conventional light guides are all composed of bundles of optical fiber wires having the same numerical aperture, in order to realize different light distribution characteristics for each branch of two branches, the respective output ends thereof. The provided diffusing lens required a lens with a different focal length. In particular, for wide-angle lenses for wide-angle light distribution, a single lens cannot provide a sufficient wide angle, and it is necessary to use two or more combination lenses (composite lenses), which hinders the downsizing of the endoscope scope tip. There is a problem that it becomes a factor and raises the manufacturing price.

In view of the above problems, it is an object of the present invention to provide an endoscope apparatus which can realize an optimum light distribution characteristic both when observing a lumen portion and when observing a flat portion. .

Another object of the present invention is to realize a different light distribution characteristic for each of the two branches of the light guide by using a single lens as a diffusing lens, to miniaturize the distal end portion of the endoscope, and to reduce the manufacturing cost. An object of the present invention is to provide an endoscope apparatus that suppresses the above.

[0012]

In order to solve the above-mentioned problems, the endoscope apparatus according to the present invention is characterized in that the illumination light incident on the incident end from the light source outside the endoscope scope is introduced into the distal end portion of the endoscope guiding middle portion. In an endoscope device that guides light by a light guide in which a plurality of optical fiber strands are bundled up to an emission end provided in the optical fiber strand of the first type having at least a first numerical aperture NA1 and NA1 The gist is that the light guide is configured by using a plurality of types of optical fiber strands including a second type of optical fiber strand having a second numerical aperture NA2.

Here, the numerical aperture NA of the optical fiber is a value obtained by taking the sine of the angle θmax which is half the maximum emission angle (or maximum reception angle) at the end face of the optical fiber, and is represented by the following equation (1). . NA = sin (θmax) (1) Further, the theoretical value of the numerical aperture calculated by using the refractive index n _{1 of the} core and the refractive index n _{2 of the} clad which form the optical fiber strand is the maximum theoretical NA (NAmaxth). And the following formula (2)
Indicated by NAmaxth = √ (n ₁ ² −n ₂ ² ) (2) As is clear from the formula (2), the numerical aperture of the optical fiber is changed by changing the refractive index of the core or the cladding. You can

A light guide is constructed by using two kinds of optical fiber wires having different numerical apertures, and the smaller numerical aperture NA.
Obtaining a narrow-angle light distribution characteristic from the optical fiber having 1
If a wide-angle light distribution characteristic is obtained from an optical fiber element wire having a larger numerical aperture NA2, the load on the diffusing lens is lightened, and the diffusing lens can be composed of a single lens.

The endoscope device according to a second aspect of the present invention is the endoscope device according to the first aspect, wherein the first type optical fiber element wire and the second type optical fiber element wire are arranged at different emission ends. And

An endoscope apparatus according to a third aspect is the endoscope apparatus according to the first or second aspect, wherein one illumination light beam is emitted from the first type optical fiber element wire and the second type optical fiber element wire. The essence is to diverge with two single lenses.

Even if the emission end of the light guide is divided into a plurality of parts for each type of optical fiber strand, a narrow-angle light distribution characteristic is obtained from the first type optical fiber strand, and the second type optical fiber is obtained. There is no change in that wide-angle light distribution characteristics can be obtained from the wires.
The single lens can be used as a diffusing lens also in the case where the optical fiber element wire is branched into a plurality of pieces and the diameter of the middle portion of the endoscope is reduced as a two-lamp illumination or a multiple-lamp illumination.

According to a fourth aspect of the present invention, there is provided an endoscope apparatus according to any one of the first to third aspects, wherein an incident end on which the light from the light source is incident on the light guide has a first region and a second region.
It is characterized in that the first type optical fiber elemental wire is arranged in the first area and the second type optical fiber elemental wire is arranged in the second area.

Area division at the entrance end includes concentric division, semicircular division, and fan-shaped division. The concentric shape is preferable in that the orientation of the optical fiber connector is not required.

An endoscope apparatus according to a fifth aspect is the endoscope apparatus according to any one of the first to fourth aspects, further comprising a light-shielding means for optionally shielding a part of incident light entering the light guide from the light source. The main point is that.

As a result, at the light incident end, the first area in which the first-type optical fiber element wires are arranged and the second area in which the second-type optical fiber element wires are arranged are divided. Therefore, the light distribution characteristics can be changed by shielding at least a part of one region or shielding one region at a higher ratio than the other region.

According to a sixth aspect of the present invention, there is provided an endoscope apparatus having a plurality of optical fibers from the light source outside the endoscope to the illumination light incident on the incident end up to the emission end provided on the distal end of the endoscope guiding portion. In an endoscope apparatus that guides light with a light guide that bundles strands, an imaging unit that captures an image of a subject illuminated by the illumination light and a part of incident light that enters the light guide from the light source are provided. A light blocking unit for arbitrarily blocking light, a high brightness region detection unit for detecting a high brightness region of an image captured by the image capturing unit, and a light blocking region for incident light by the light blocking unit according to a region where high brightness is detected It is a gist to have the control means for performing.

For example, when high brightness is detected in the central portion of the photographed image, the incident end where the first-type optical fiber element wire having a narrow-angle light distribution characteristic is arranged is shielded from light and the central portion of the central portion is blocked. Focus on reducing illuminance. On the other hand, when high brightness is detected in the peripheral portion of the captured image, the total illuminance is reduced by blocking the incident end where the second-type optical fiber element wire having a wide-angle light distribution characteristic is arranged. Lower. In this way, appropriate illuminance can be obtained regardless of whether the object to be imaged is the luminal portion or the flat portion, the object can be easily observed, and the examination time can be shortened and accurate diagnosis can be performed.

The high-intensity part detecting means integrates the analog video signal corresponding to the central portion of the screen by the timing signal generated in synchronization with the horizontal / vertical synchronizing signals, and displays the screen when the integrated value exceeds a predetermined value. It is possible to use a detection unit that determines that the central portion is the high-luminance portion. With respect to the peripheral area of the screen, it is possible to determine whether it is the high brightness portion or not by using the same means.

Further, in the endoscope apparatus having the frame memory for storing the digital video signal, the address bus and the data bus of the frame memory are monitored, and the frame memories respectively corresponding to the screen central portion and the screen peripheral portion are respectively monitored. The number of times that the data in the predetermined address range exceeds the predetermined brightness value is counted, and when the count value exceeds the predetermined value, it is determined that the central part of the screen or the peripheral part of the screen is the high brightness part. Means may be used.

[0026]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a configuration diagram showing a first embodiment of an endoscope apparatus according to the present invention. In FIG. 1, the endoscope device 1 includes an endoscope scope main body 2 and an endoscope processor device 3. Endoscope processor device 3
Includes a light source device 4, an air / water supply device 5, a video processor 6, and a monitor device 7.

The endoscope scope main body 2 is equipped with a diffusion lens 21 for wide-angle illumination, a diffusion lens 22 for narrow-angle illumination, an objective lens 23 and an image pickup device 24, and a tip portion having an air supply hole 25 and a water supply hole 26. 27, a long and flexible guiding middle portion 28 following the tip portion 27, an operation knob (not shown) for operating the bending direction of the tip portion 27, and an operation button (not shown) for controlling air supply / water supply. ), And a long universal cord 30 that is pulled out from the operation unit 29 and connects the operation unit to the endoscope processor device 3. A forceps hole (not shown) extending from the operation portion 29 to the tip portion 27 is provided for treatment.

A connector portion 31 is provided at the tip of the universal cord 30 and is detachably connected to the connector portion 32 of the endoscope processor device 3. The universal cord 30 is a light guide 33 for illumination, an air / water supply tube 34, and a signal cable 35 of the image pickup device 24, which are integrated into a single cable. 4, air / water supply device 5,
It is connected to the video processor 6.

The light source device 4 includes a light source 41 using a xenon lamp and a power source device 42 for supplying electric power to the light source.
A reflecting mirror 43 arranged behind the light source, a condenser lens 44 arranged in front of the light source, a diaphragm mechanism 45 for adjusting the amount of light, a light shielding mechanism 46 for changing the light distribution characteristic, A light source cooling fan (not shown) is included.

The light guide 31 guides the light from the light source device 4 from the connector portion 31 of the universal cord 30 to the two diffusion lenses 21 and 22 provided at the endoscope tip portion 27. As shown in FIG. 2A, in the connector portion 31, which is the light incident end, the inside has a small NA (for example, N
(A = 0.5) A large number of first-type optical fiber wires 81 are bundled into a circular bundle, and NA is large outside the bundle (for example, NA = 0.
7) A large number of the second-type optical fiber element wires 82 are arranged concentrically, and the outside thereof is bound by a fiber holding frame 83.

The bundle of optical fiber strands forming the light guide 33 has the above-mentioned concentric circle arrangement inside the universal cord 30 from the incident end. There are two branches. And NA
The first type optical fiber element wire having a small diameter becomes a bundle 36 having a small diameter with a circular cross section, and the second type optical fiber element wire having a large NA becomes a bundle 37 having a large diameter having a circular cross section.

The light guide thus branched into two branches for each NA passes through the endoscope guiding middle portion 28, and at the endoscope distal end portion 27, from each branch end portion to each diffusion lens. Emit to 21 and 22. Narrow-angle light distribution is performed from the bundle 36 of the first-type optical fiber wires having a small NA, and N
Since the wide-angle light distribution is performed from the bundle 37 of the second type optical fiber element wires having a large A, the load on each of the diffusion lenses 21 and 22 is light, and a single lens, for example, a plano-concave lens can be used to form the diffusion lens. it can. When the thickness 36 of the first type optical fiber element wire bundle and the thickness of the second type optical fiber element wire bundle 37 are made uniform, the respective diffusion lenses should have the same shape and the same characteristics. Can be used.

FIG. 3 is a graph showing the light distribution characteristics in a plane perpendicular to the optical axis of the endoscope, and FIG. 3 (a) shows the light distribution characteristics when observing the lumen portion, and FIG. ) Indicates the light distribution characteristics when observing the flat portion. In either case, the sum of the narrow-angle light distribution from the bundle 36 of the first-type optical fiber element wires having a small NA and the wide-angle light distribution from the bundle 37 of the second-type optical fiber element wires having a large NA is obtained. It has a comprehensive light distribution characteristic. As is clear from FIG. 3, when observing a flat surface portion, the intensity of the narrow-angle light distribution is reduced to prevent halation from occurring in the central portion of the screen of the captured image. The observability is improved.

A light shielding mechanism 46 for changing the light distribution characteristic
Is a chopper 47 having a circular light-shielding portion that intermittently shields between the light source 41 and the incident end of the light guide 33, a motor 48 for rotating the chopper 47, and the chopper 47 and the motor 48 on the optical axis of the light source 41. A rack 49 that moves back and forth (Z axis direction) along with a pinion 5 that meshes with the rack 49.
It is composed of a forward / reverse rotatable motor 51 that drives 0.

The motor 51 is controlled for forward rotation, stoppage and reverse rotation by a control signal from a high brightness part detection circuit 69 provided inside the video processor 6.

FIG. 4 is a block diagram showing the configuration of the video processor 6. In the figure, the CCD drive circuit 71 sends a drive signal to the CCD, which is the image pickup device 24, based on the timing signal generated by the synchronization generation circuit 72. The signal read from the CCD is amplified by the preamplifier 61, the level is adjusted by the AGC 62, and the ADC is
Analog-to-digital conversion is carried out by 63 and output as a digital video signal.

Next, the digital video signal is subjected to color signal processing by the color separation circuit 64 in accordance with the color filter on the front side of the CCD, and a luminance signal (Y) and two color difference signals (RY, BY). Are the field memories 65,
66 and 67. Field memory 65, 6
The signals read from 6 and 67 are converted into NTSC signals by the encoder 68 and output to the monitor 7.

The high-brightness part detection circuit 69 monitors the read address and read data of the Y field memory 65, takes in the data of the read address range corresponding to the preset central portion of the screen, and exceeds the predetermined brightness value. The number of data is counted for each field. Then, when this count value exceeds a predetermined value, it is determined that halation may occur in the central portion of the screen, and in order to reduce the intensity of the narrow-angle light distribution, the light shielding mechanism 46 is provided with the chopper 47 in the -Z direction. Send control signal to transfer.

The light-shielding mechanism 46, which has received the control signal from the high-brightness part detection circuit 69, rotates the motor 51 to rotate the pinion 50 counterclockwise and moves the rack 49 in the -Z direction. As a result, the ratio of the bundle of the first-type optical fiber element wires 81 arranged at the center of the incident end of the light guide 33 is shielded by the chopper 47, and the illuminance decreases at the center of the screen of the captured image. It is possible to display on the monitor device 7 an image that is easy to observe without halation.

Next, another embodiment of the present invention will be described. FIG. 2B shows the arrangement of the optical fiber strands at the light guide entrance end in the second embodiment. The bundle of the first type optical fiber strands 81 is a semicircular shape in the lower half of the circular entrance end. And the bundle of the second type optical fiber element wires 82 is arranged in a semicircular area in the upper half of the circular entrance end. In this case, the selective light shielding by the chopper is performed by moving the chopper in the vertical direction. Other configurations are the same as those of the first embodiment, and the effects thereof are also the same as those of the first embodiment.

FIG. 2C shows the arrangement of the optical fiber strands at the light guide entrance end in the third embodiment. The first type optical fiber strand 81 and the second type optical fiber strand are shown in FIG. The line 82 and the line 82 are mixed and arranged at the circular incident end.
In this case, although it is impossible to selectively shield the light with the chopper, a narrow-angle light distribution is obtained from the first-type optical fiber element wire 81 and a wide-angle light distribution is obtained from the second-type optical fiber element wire 82. However, the burden on the diffusing lens is lightened, and the diffusing lens can be configured with a single lens.

Although the preferred embodiments have been described above, these do not limit the scope of the present invention. Although two types of optical fiber strands are used in the embodiment, it is possible to use optical fiber strands having three or more kinds of numerical apertures or to select an arbitrary branch number of the light guide. It is clear that

Further, in the above embodiments, the electronic endoscope provided with the electronic image pickup means has been described, but the present invention is applied to the illumination light guide of the optical endoscope apparatus using the light guide for the observation system. It is also possible to apply the invention.

[0044]

As described above, according to the present invention, the first-type optical fiber strand having the first numerical aperture NA1 and N
By configuring the light guide using a plurality of types of optical fiber strands including a second type optical fiber strand having a second numerical aperture NA2 larger than A1, the narrowness of the first type optical fiber strand is reduced. The angle light distribution characteristic and the wide-angle light distribution characteristic of the second type optical fiber element are compatible with each other, and a uniform illuminance within the field of view can be obtained, so that the observability by the endoscope is improved. .

Further, it becomes possible to configure a diffusion lens with a single lens, without the need for a lens having different characteristics for each of the two branches of the light guide or a combination lens, and the tip portion of the endoscope can be made compact. And the manufacturing cost can be suppressed.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of an endoscope apparatus according to the present invention.

FIG. 2 is a diagram showing an arrangement region of two types of optical fiber element wires at a light guide entrance end.

FIG. 3 is a graph showing a light distribution characteristic of the endoscope device according to the present invention.

FIG. 4 is a block diagram showing a configuration of a video processor of the endoscope apparatus according to the present invention.

FIG. 5 is a configuration diagram showing a configuration of a conventional endoscope apparatus.

FIG. 6 is a graph showing a light distribution characteristic of a conventional endoscope device.

[Explanation of symbols]

1 Endoscope Device 2 Endoscope Scope Body 3 Endoscope Processor Device 4 Light Source Device 5 Air / Water Supply Device 6 Video Processor 7 Monitor Device 21 Narrow Angle Light Diffusing Lens 22 Wide Angle Light Diffusing Lens 33 Light Guide 36 Bundle of type 1 optical fiber strands 3
7 Bundle of second-type optical fiber strands 46 Light-shielding device 81 First-type optical fiber strands 82 Second-type optical fiber strands

Claims (6)

[Claims] 1. A light guide, which bundles a plurality of optical fiber strands, guides illumination light incident on an incident end from a light source outside the endoscope scope to an emission end provided at a distal end of the endoscope guiding middle part. In an endoscope apparatus that emits light, a plurality of types including at least a first-type optical fiber strand having a first numerical aperture NA1 and a second-type optical fiber strand having a second numerical aperture NA2 larger than NA1 An endoscope apparatus in which the light guide is configured by using the optical fiber element wire. 2. The endoscope apparatus according to claim 1, wherein the first-type optical fiber element wire and the second-type optical fiber element wire are arranged at different emission ends, respectively. 3. The illumination light emitted from the first type optical fiber element wire and the second type optical fiber element wire is diverged by one or two single lenses. The endoscope apparatus according to 2. 4. The light guide is divided into a first region and a second region at which an incident end on which light from a light source is incident is divided into first and second regions.
The optical fiber strand of the first type is arranged in the region of 1 and the optical fiber strand of the second type is arranged in the second region. Endoscope device. 5. The endoscope according to claim 1, further comprising a light shielding unit that arbitrarily shields a part of incident light entering the light guide from the light source. apparatus. 6. A light guide, which bundles a plurality of optical fiber strands, guides illumination light incident on an incident end from a light source outside the endoscope scope to an emission end provided at a distal end of the endoscope guiding middle part. In the illuminating endoscopic device, an image capturing unit that captures an image of a subject illuminated by the illumination light, a light shielding unit that arbitrarily shields a part of incident light entering the light guide from the light source, and the image capturing A high-brightness part detection means for detecting a high-brightness part of the image picked up by the means; and a control means for controlling the light-shielding area of the incident light by the light-shielding means according to the part where a high brightness is detected. A characteristic endoscopic device.