JPH0216888B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a length measuring endoscope that can measure the distance to an object or the size of an observation region with a simple structure.

[Technical background of the invention and its problems] In recent years, endoscopes have been widely used in the medical and industrial fields.

The endoscope is used to measure the size of a lesion, for example, in order to diagnose a lesion that has occurred on the inner wall of the stomach, or to investigate how the lesion changes over time. It is often necessary to do so.

In conventional endoscopes or length measuring endoscopes,
When determining the size of a lesion or other object to be examined based on the distance or within the field of view, detection has been performed based on the amount of adjustment when adjusting the focus of the observation optical system of the endoscope. In this case, due to the characteristics of the optical system in the endoscope, a lens with a large depth of field is used, and the object to be examined has little change in color or pattern, so it is difficult to perform accurate focus adjustment, and it is necessary to It was difficult to obtain a measurement accuracy of

In addition, in the conventional example disclosed in Japanese Patent Publication No. 51-45911, a light projection device disposed on the distal end side of the insertion section allows the light to intersect with the optical axis of the objective lens system at a large angle on the object side. By projecting a spot light as shown in FIG. It is configured to be able to measure distances, etc. from the scale corresponding to the spot position. In this conventional example, parallel spot light is used so that the size of the spot does not change with distance, so it becomes difficult to observe the spot at a long distance, and when the object is illuminated by the illumination optical system, It becomes difficult to identify the location of the spot.

In addition, in the conventional example disclosed in Japanese Utility Model Application Publication No. 53-80284, an optical system for index projection is provided in addition to the normal observation optical system and illumination optical system, resulting in a complicated structure. This method has disadvantages in that the manufacturing cost is high, the outer diameter of the insertion portion is increased, or the distal end of the insertion portion that cannot be bent is lengthened, which increases the pain caused to the patient during insertion.

Furthermore, since the projected index light beam is spot light, it has the disadvantage that it is almost impossible to distinguish the index in the state of illumination with the illumination light as described above.

Furthermore, in the conventional example disclosed in Japanese Utility Model Application Publication No. 53-80284, a dedicated target projection optical system is provided separately from the illumination optical system for observing the object. Therefore, it is difficult to visually recognize the index beam projected from other sources in bright illumination light, and a strong index beam is required, which has the drawback of low contrast and difficulty in viewing. Furthermore, since there is a dedicated target projection optical system separate from the illumination optical system, the configuration becomes complicated and the diameter of the insertion section or the distal end of the insertion section becomes large.

The present invention was devised in view of these circumstances, and consists of an index made of a light-shielding member to realize illumination of the object and projection of the index using a single illumination optical system.
As a result, the contrast of the index can be increased by changing the degree of shading of the illumination light, and by using a color filter, the index can be colored, making it possible to obtain an index with good visibility. It is an object of the present invention to provide a length measuring endoscope that has a simple configuration and can be realized without increasing the diameter of the insertion section or the distal end of the insertion section.

In order to achieve the above object, the present invention provides an endoscope that includes an illumination optical system that illuminates an object, and an observation optical system that allows the illuminated object to be imaged and observed by an objective lens. At the tip of the illumination optical system, an index made of a light-shielding member and a lens that shares the projection of the index and the projection of illumination light are disposed, and the object is determined by the position of the projected image of the index that appears within the observation field. A scale capable of displaying the distance to the object or the size of the object part is formed at an appropriate position on the observation optical system near the position where the image is formed by the objective lens or behind the position.

[Embodiments of the Invention] The present invention will be specifically described below with reference to the drawings.

1 to 4 relate to a first embodiment of the present invention, FIG. 1 shows the appearance of the first embodiment, and FIG. 2 schematically shows the main parts of the optical system of the first embodiment, FIG. 3 shows a projected image of the projected target and the shape of the target, and FIG. 4 shows an eyepiece field image observed from behind the eyepiece.

As shown in FIG. 1, the length measuring endoscope 1 of the first embodiment (which can measure the distance or size of an object) has an elongated and flexible insertion section 2, and a rear end of the insertion section 2. A large-diameter operation section 3 connected to the end side, an eyepiece section 4 formed on the rear end side of the operation section 3, and an eyepiece section 4 that extends to the outside from the side of the operation section 3 and can be attached to the light source device 5. It consists of a flexible universal cord (light guide cable) 6 to which a connector is attached.

As shown in FIG. 2, the insertion section 2 includes a rigid tip (configuration) section 8 that accommodates an observation optical system, etc.
and a bending portion 9 are successively arranged from the tip side, and a bending operation knob 10 formed on the operation portion 3.
By rotating the bending portion 9, the bending portion 9 can be bent left and right or up and down.

A light guide 11 formed of a flexible fiber bundle for transmitting illumination light is inserted into the universal cord 6.
is an illumination light transmission means in an illumination optical system that emits the light of the illumination lamp 12 irradiated onto one end surface mounted on the light source device 5 from the other end surface,
It is bent by the operating part 3 and further inserted into the insertion part 2, and its distal end side is fixed to the inner wall of a through hole formed in the distal end forming part 8, as shown in FIG.

On the tip surface of the light guide 11, for example, as shown in FIG. 3, an indicator member 13 is disposed, which is disk-shaped and has a circular (ring-shaped) indicator 13A with a radius h on one side. , a projection (imaging) lens (system) 14 for projecting the index 13A onto the test object (object) is disposed in front of the index 13A.
Note that the index 13A is disposed at the focal length f of the lens 14, and within the conical illumination range angle that forms the angle α with the optical axis, the index 13A is located at the angle β with the optical axis. They are concentric conical shapes that project forward.

On the other hand, inside the insertion section 2, there is an image guide 1 for image transmission formed of a flexible fiber bundle.
6 is inserted through the image guide 16, and the distal end side of the image guide 16 is fixed to the inner wall of the through hole formed in the distal end forming portion 8 with a base member. An objective lens 17 for image formation is arranged in front of the image guide 16, and an object in front within an imaging range angle (objective field of view) that forms an angle θ with the optical axis is placed on the tip surface of the image guide 16. An observation optical system is formed in which an image is formed, transmitted to the rear end surface on the proximal side by the image guide 16, and can be magnified and observed from behind an eyepiece lens 18 disposed behind the rear end surface.

In this first embodiment, a scale member 19 having a scale 19A in black or the like on a transparent glass plate or the like is provided on the rear end surface on the proximal side of the image guide 16, as shown in FIG. This scale 19
A is provided along a straight line connecting the optical axis of the objective lens 17 and the optical axis of the tip of the light guide 11 within the eyepiece visual field as seen from the eyepiece section 4 .

That is, as shown in FIG.
As shown in A and B-B (shown in a perspective view for ease of understanding), when located at distances L ₁ and L ₂ from the tip surface (front end surface) of the tip component 8, it is projected in a ring shape. The size of the index 13A and the circular imaging range of the object imaged by the objective lens 17 also differ. In this case, the projected index 13A coming into the objective field (or similarly in the ocular field) of the objective lens 17
When observing the position on the straight line connecting the optical axis of the lens 14 and the optical axis of the objective lens 17 where a part of the circle of the circular index 13A intersects (crosses) the straight line, the distance is large. As it becomes larger, it gradually approaches the optical axis of the objective lens 17 (or approaches the center of the field of view), and as it becomes larger, it moves away from the optical axis (or moves away from the center of the field of view) (in the opposite direction to the direction of approaching the optical axis), The scale 19A is displayed along the direction of movement so that the distance can be determined. In FIG. 4, the vertical straight line coincides with the straight line connecting the optical axis of the objective lens 17 and the optical axis of the lens 14, and along this straight line, the distance gradually increases from the bottom to the top. A scale 19A is provided to represent the image.

In addition, with respect to the angle θ of the objective field of view, the index 13A
By setting the projected angle β slightly larger, the index 13A moves (largely) along with the distance within the field of view, making it possible to read the distance accurately.

The operation of the first embodiment configured in this way will be described below.

The universal cord 6 of the length measuring endoscope 1 of the first embodiment is attached to the light source device 5, and the power switch of the light source device 5 is turned on to irradiate the end face of the light guide 11 with light from the illumination lamp 12. This emitted light is
The lens 14 illuminates the area within the illumination angle α from the tip surface of the light guide 11, and the index 13A with the radius h of the index member 13 is illuminated by the lens 14 at an angle β in a circular shape toward the object. indicator 13A
Project an image of

On the other hand, since the objective viewing angle of the objective lens 17 is θ, the position where the image of the circular index 13A projected together with the illumination by the illumination optical system appears within the field of view is located at the position of the object as shown in FIG. Depends on distance. For example, in FIG. 2, if there is an object at a distance L ₁ , the image of the index 13A is in a position close to the center of the visual field, and a part of the circle of this image becomes the scale member as shown in FIG. 19 (the image of the index 13A is indicated by the same symbol 13A in Fig. 4), so the distance can be determined by reading the position of the scale 19A where it intersects. be able to. When the object is further away, the position where the projected indicators 13A intersect moves to the upper side in FIG. 4, and by reading the scale 19A at the intersecting position, the distance to the object can be determined. .

In this way, according to the first embodiment, since the index 13A is projected together with the illumination light, distance information can always be obtained within the observation screen.
It is possible to perform operations appropriately without misunderstanding the sense of perspective, and it is also easier to estimate the size of the object.

For example, when the distance L to the object is determined by the scale 19A, the radius r in the projected image when the index 13A with radius h is projected onto the object is r=h(L-f)/f. , if the distance L is sufficiently larger than the focal length f (that is, L≫f), then r=h
Depending on L/f, the size of the affected area within the field of view can also be determined from the size of this radius r, and by comparison, it can be known more accurately. In this case, the projected image is circular, so even if a part of it is difficult to see, it can be determined by extrapolating from other parts, so the distance and size can always be known. Very useful for diagnosis and observation.

FIG. 5 shows a scale 19B in which the magnification of the visual field that changes depending on the distance of the object is displayed on the scale member 19.
2 shows an ocular visual field image in a second example using the . The rest is the same as the first embodiment. In this case, the circle of the projected image of the index 13A is the scale 19.
Since it is enlarged (or reduced in some cases) by the value of the scale 19B that intersects B, the actual length is obtained by dividing by that value. In FIG. 5, index images 13A and 13A' appearing at the lower and upper sides of the visual field represent images observed from the ocular visual field when projected onto a nearby object and a distant object, respectively. In this case as well, by comparing the size of the projected image of the index 13A observed within the visual field, the size of the observed area such as the affected area within the visual field or the distance to the object can be determined. It can also be used as a clue.

FIG. 6 shows an eyepiece visual field image in the third embodiment.

That is, in this embodiment, the scale member 19
The scale 19C in is a certain length (for example, 2
[mm]) is displayed within the field of view. For example, in FIG. 6, if the projected image 13A1 of the circular index _13A intersects at the upper side of the figure within the field of view, the length of the symbol c above for the object within the field of view is This indicates that it corresponds to a certain length of 2 [mm].

Similarly, in the case of a short distance where the projected index image 13A ₂ intersects at the bottom of the same figure, the length of code d is 2 in the field of view of the object observed at that distance. This corresponds to [mm].
In other words, the length from the top point of the field of view to the position where the projected index image 13A ₁ (or 13A ₂ ) intersects is equivalent to 2 [mm] for the object observed within the field of view. Show that. Therefore, by comparing the length or size of an object whose length or size is desired to be measured, the length or size of the object can be determined by comparing the length or size of the affected area with the above-mentioned length. Since a fixed length such as [mm] is photographed together with the object within the field of view, it is very useful for diagnosis, etc.

FIG. 7 shows an eyepiece visual field image in the fourth embodiment.

In this embodiment, the index 13B attached to the index member 13 is not circular but linear.
In this case, the indicator 13B becomes easier to see. Other than this, the second embodiment is the same as the first embodiment.

FIG. 8 shows the light guide 11 in the first embodiment.
The main part of the fifth embodiment is shown in which a filter 21 is disposed on the end face of the fifth embodiment.

In this embodiment, the light from the light source lamp 12 is made monochromatic by the filter 21, and the image of the index 13A projected is shown by a black line.

Note that the shapes of the indicators 13A and the like are not limited to those described above.

In addition, the projected images of the indicators 13A, 13B can be displayed in blue, red, green, etc. by configuring the indicators 13A, 13B, etc. with a filter that passes only light of a certain wavelength. In this case, it is also possible to select a color that is easier to see depending on the color scheme of the object being observed.

Furthermore, in each of the embodiments described above, the light guide 11 formed of a fiber bundle is used in the illumination optical system, but a lamp and a high-intensity light emitting diode are installed behind the index 13A on the distal end side of the insertion section 2 in FIG. It is also possible to arrange lighting means such as the following.

Furthermore, a scale member 1 disposed within the eyepiece section 4
9 can be detached and replaced, so that, for example, the first embodiment and the second embodiment can be used interchangeably as needed.

The scale member 19 is not limited to being disposed on the eyepiece 4 side, but may be disposed at an appropriate position in the observation optical system near the position where the image is formed by the objective lens 17 or behind that position. be able to.

Moreover, the above-mentioned indicator member 13 or scale member 1
A liquid crystal plate or the like may also be used for at least one of the elements 9. For example, when used in the index member 13, by operating a switch that turns on and off the application of voltage,
It is also possible to display the indicators 13A, 13B, etc. in areas that do not pass through the liquid crystal plate, or to select not to display the indicators 13A, 13B, etc. when they become a hindrance during observation. Further, when used as the scale member 19, the scale 19A and the like can be displayed as necessary, or can be selected not to be displayed when unnecessary. Furthermore, you can switch between displaying the scale 19A for distance and displaying the scale 19B for knowing the size of an object, and you can also switch between displaying it in conjunction with the index side and not displaying it. It can also be configured to control.

Note that the present invention is applicable not only to a flexible endoscope that uses the image guide 16 as an image transmission means, but also to a rigid endoscope that uses a relay optical system. In addition, a CCD (charge coupled device) and a BBD (bucket brigade device) are installed at the imaging position of the objective lens 17.
A solid-state image pickup device using a camera, etc. is installed, and the image formed on the surface of the solid-state image pickup device is photoelectrically converted, transmitted through a signal cable inserted through the insertion section 2, and displayed on a display device such as a cathode ray tube. It can also be applied to structural endoscopes. In this case, the scale member may be provided on the front surface of the solid-state image sensor, or the scale may be provided on the surface of the display device without using the scale member.

Furthermore, the present invention can be applied not only to direct-viewing type flexible endoscopes, but also to rigid endoscopes using a relay optical system as an image transmission means, as well as oblique-viewing and side-viewing flexible endoscopes. be.

[Effects of the Invention] As explained above, according to the present invention, the index is configured with a light-shielding member, so that illumination of the object and projection of the index can be realized by one illumination optical system, and as a result, the illumination light can be blocked. It is possible to increase the contrast of the index depending on the condition, and it is also possible to color the index using a color filter, making it possible to obtain an index with good visibility. This has the advantage that it can be realized without increasing the diameter of the insertion section or the distal end of the insertion section.

[Brief explanation of drawings]

1 to 4 relate to a first embodiment of the present invention, FIG. 1 is a schematic perspective view showing the external appearance of a length measuring endoscope of the first embodiment, and FIG. 2 is an optical diagram of the first embodiment. FIG. 3 is an explanatory diagram showing the system, and FIG. 3 is an enlarged view of the main parts of the illumination optical system. FIG. Diagram a
A cross-sectional view showing the shape of the index by cutting along line C-C of
FIG. 4 is an explanatory diagram showing the ocular visual field image seen from the eyepiece section, FIG. 5 is an explanatory diagram showing the ocular visual field image in the second embodiment of the present invention, and FIG. 6 is an explanatory diagram showing the ocular visual field image in the third embodiment of the present invention. FIG. 7 is an explanatory diagram showing an ocular visual field image in a fourth embodiment of the present invention, and FIG. 8 is an explanatory diagram showing a filter in a fifth embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Length measuring endoscope, 2... Insertion section, 4... Eyepiece section, 5... Light source device, 6... Universal cord, 8... Tip component, 11... Light guide,
12...Light source lamp, 13...Indicator member, 13
A, 13B... Index (image), 14... Projection lens, 16... Image guide, 17... Objective lens, 18... Eyepiece, 19... Scale member, 19A, 19B, 19C... Scale , 21...
...filter.

Claims (1)

[Scope of Claims] 1. In an endoscope that includes an illumination optical system that illuminates an object and an observation optical system that forms an image of the illuminated object using an objective lens so that it can be observed, the illumination optical system At the tip of the indicator, an indicator made of a light-shielding member and a lens that shares the projection of the indicator and the projection of illumination light are arranged. A length-measuring endoscope characterized in that a scale capable of displaying the distance or the size of the target region is formed at an appropriate position of the observation optical system near the position where the image is formed by the objective lens or behind the position. . 2. The length measuring endoscope according to claim 1, wherein the index is circular or linear. 3. The length measuring endoscope according to claim 1, wherein the index is projected in one of black, red, green, and blue by illumination light. 4. The length measuring endoscope according to claim 1, wherein the illumination optical system is formed using a light guide fiber formed of a fiber bundle, a lamp, or a light emitting diode. 5. The length measuring endoscope according to claim 1, wherein the illumination optical system is made monochromatic by a filter and projects the index as a black line. 6. The length measuring endoscope according to claim 1, wherein the indicator is configured such that the display thereof is selectively controlled by controlling the application of voltage to a liquid crystal plate. 7. The length measuring endoscope according to claim 1, wherein the scale is formed on a liquid crystal plate whose display is controlled by controlling the application of voltage.