JPS5929217A - Endoscope using tempered cover glass - Google Patents

Abstract

PURPOSE:To suppress the generation of failure accidents and to assure safety by closing at least one among a window part for illumination, a window part for an objective and a window part for an eyepiece with cover glass formed thereon with ion exchange layers. CONSTITUTION:A hard endoscope 11 consists of an insertion part 12, an operation part 14 and an eyepiece part 15. An inside tube 18 and a light guide fiber 17 are inserted into the outside tube 16 of the part 12. Cover glass 19 is fixed to the forward end side of the tube 18 to close the window part for an objective. The glass 19 are provided with ion exchange layers 27a, 27b which are chemically tempered by ion exchanging, thereby preventing the generation of failure accidents and assuring safety.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an endoscope with a reinforced cover glass that can suppress the occurrence of accidents such as breakage of the cover glass and improve safety.

In recent years, by inserting a long and narrow insertion section into a body cavity, it is possible to observe internal organs in the body cavity and, if necessary, collect in-vivo tissues using forceps inserted into the forceps channel to diagnose the affected area in detail. Medical endoscopes are widely used. Also, in the industrial field, industrial endoscopes are used as boilers.

It is also used for maintenance purposes, such as observing the condition inside pipes of chemical plants, etc., and collecting and inspecting deposits on the inner surface of pipes.

The above-mentioned endoscopes are classified into flexible endoscopes having a flexible and bendable insertion portion, and rigid endoscopes having a rigid insertion portion having a substantially linear shape.

In these endoscopes, when the insertion section is inserted, the illumination optical system transmits the illumination light supplied to the proximal side and emits the illumination light to the object side on the distal end side of the insertion section; An observation optical system is provided that can form an image of the illuminated object and observe it from behind the eyepiece on the hand side.

FIG. 1 shows the distal end side of the insertion section in a conventional rigid endoscope.

In the figure, a light guide fiber (not shown) that transmits illumination light and emits it from the distal end surface is inserted into an outer tube 2 of the insertion section 1, which serves as the outer cover of the insertion section 1. An objective cover glass 4 is passed through a lens barrel 3 for housing an optical system inserted adjacent to this light guide fiber, and an optical image of the object is formed by objective lenses 5, 5, and the optical image is transferred to a relay (not shown). An observation optical system is configured in which the image is transmitted to the rear operating unit side through an image transmission means such as a lens system, and is observed from behind the eyepiece.

The (objective) cover glass 4 is attached to the inner periphery of the front end of the lens barrel 3 in front of the objective lens 5.degree. 5 via a cover glass attachment frame 6. In addition, the cover glass mounting frame 6 is
It is fixed by solder or adhesive 7 or the like at the outer periphery of the front end surface of the cover glass mounting frame 6 which is fitted into the lens barrel 3, for example.

In order to reduce the possibility of breakage, the cover glass 4 attached in this manner is placed, for example, by a distance d behind the front end surface of the lens barrel 3 or a protrusion such as the adhesive 7 that slightly protrudes from the front end surface. Since it is fixed at a position where a recess is formed, when inserted into a body cavity or the like, water droplets and the like tend to accumulate in the recess. Therefore, since the water droplets refract the incident light like a lens, the optical image of the object formed by the objective lenses 5, 5 at the rear position may be distorted, or bubbles may form in the recesses in body fluids. This has the disadvantage that it becomes difficult to obtain clear images due to the adhesion of particles.

On the other hand, in order to eliminate the above-mentioned drawbacks, it is possible to make the front end surface of the cover glass protrude from the insertion tube distal end surface (front end surface).
There is a drawback that the cover glass may be damaged if it is applied to an instrument during operation of the endoscope or cleaning process.

In this case, if the thickness of the cover glass is increased, the breakage can be somewhat reduced, but even if the thickness is increased within a range that does not interfere with the rear optical system, there is no significant improvement.

Therefore, when used, there is a risk that the cover glass may have cracks, and if the endoscope with the crack is inserted into a patient's body cavity, there is a risk of dropping glass fragments. There is a drawback that there is a risk of accidentally inserting the endoscope into a body cavity and damaging internal organs.

The present invention has been made in view of the above-mentioned points, and includes a strengthened cover glass that suppresses breakage accidents and ensures safety by forming a curved ion exchange layer on the surface side of the cover glass. The purpose is to provide a mirror.

Hereinafter, the present invention will be specifically described with reference to the drawings.

FIG. 2 shows a rigid endoscope according to the first embodiment of the present invention;
The figure shows an enlarged view of the vicinity of the cover glass, which is the main part of FIG. 2.

In these figures, the rigid endoscope 11 of the first embodiment is
A rigid and elongated insertion section 12 to be inserted into a body cavity has a rear end of the insertion section 12 with a large diameter and a LightGytro metal section 13 to which a connection end of a light guide cable from a light source device (not shown) is attached. It is composed of an operating section 14 and an eyepiece section 15 that accommodates an eyepiece optical system on the rear end side of the operating section 14.

Inside the outer tube 16 of the insertion section 12, there is a light guide fiber 17 that transmits illumination light, and an inner tube 18 that is eccentric to the upper side.
is inserted. On the distal end side of this inner tube 18, a first
In the illustration, a (objective) cover glass 19, which is a main part of the embodiment, is fixed directly (or via a mounting frame or the like) to close the objective window. In addition, in the illustration, the front end surface of the cover glass 19, which is the end surface facing the outside, is fixed so as to be in contact with the surrounding front end surface and the road surface.

A lens portion is fitted and inserted behind the cover glass 19, and a rod-shaped objective lens 2 is provided at the front end of the lens portion.
1 is fixed, and an objective lens 22 having a concave portion formed on the rear surface side by bonding the left side of the rear end circumferential surface to the front end circumferential surface of the rod-shaped objective lens 21 is fixed.

In the lens section, an array of objective lenses is disposed behind the rod-shaped objective lens 21 via a spacing ring n serving as an intervening member for maintaining a predetermined spacing.

As a means for transmitting the optical images formed by these objective lenses 22, 21, and 24 to the rear eyepiece side, there is a spacer ring 25A in the lens barrel m behind the objective lens.
Relay lenses 26A + 26B t... forming a relay lens system are disposed via lenses 25B, . . . , respectively.

By the way, the cover glass 19 is chemically strengthened by ion exchange.

That is, chemical strengthening of glass by ion exchange involves exchanging alkali ions in the surface layer of the glass with other types of alkali ions to strengthen the glass.

The ionic radius of alkali metal ions increases in the order of Li+, Na+, and K+, but in order to strengthen glass by ion exchange, the alkali ions in the original glass are replaced with alkali ions that have a larger ionic radius. There are two ways to strengthen the metal: one is to strengthen it by replacing it with an alkali ion having a smaller ionic radius.

When the alkali ions in the original glass are replaced with larger alkali ions, the surface layer swells and compressive stress is generated there, but the compressive stress is relaxed if the temperature is above the strain point. Therefore, when the alkali ions in the original glass are strengthened with larger alkali ions, it is generally done at a temperature below the strain point. It is said that the strength of a glass article strengthened by this method is improved by about 2 to 10 times compared to before strengthening.

On the other hand, when the alkali ions in the original glass are replaced with alkali ions having a smaller ionic radius, the surface layer contracts and cracks occur at temperatures below the strain point, but at temperatures above the strain point the strain due to contraction eases. be done. For example, if the lithium ion is replaced with a lithium ion having a small ionic radius, the surface becomes a low-expansion glass and is strengthened. Therefore, when strengthening large alkali ions in the raw glass with smaller lithium ions, it is generally done at a temperature above the strain point.

This is said to improve the strength of the strengthened glass article by about twice as much as before strengthening.

Chemical strengthening of glass by ion exchange has the great advantage that it can be easily applied to articles with complex shapes compared to strengthening methods by air-cooling strengthening.

The above raw glass is actually subjected to ion exchange treatment, and the raw glass (
When replacing Na+ in a member) with Na+ having a larger ionic radius, for example, by immersing it in a potassium nitrate bath or the like and taking it out, the thickness of the cover glass 19 is about 0.5 m as shown in Fig. 3. Approximately 20 Cμm from the surface] to 10
The ion exchange layers 27a and 27b with a thickness of 0 [μm] can be provided.

By forming the ion exchange layers 27a and 27b, it is possible to obtain a strength approximately 2 to 6 times that of the original cover glass.

Ion exchange layers 27a and 27b reinforced in this way
According to the rigid endoscope 11 of the first embodiment, which uses the cover glass 19 formed with a Therefore, the cover glass 19 will not be damaged during normal use.

Therefore, the risk of dropping glass fragments into the patient's body cavity and the risk of damaging organs in the body cavity due to broken glass parts are eliminated, and safety can be improved.

FIG. 4 shows a flexible endoscope according to a second embodiment of the present invention, and FIG. 5 shows an enlarged view of the distal end side of the insertion portion in FIG. 4.

In these figures, the flexible endoscope 31 includes an elongated and flexible insertion section 32, a large-diameter operation section 33 connected to the rear end of the insertion section 32, and a large-diameter operation section 33 provided on the side of the operation section 33. It is composed of a flexible light guide cable 34 that transmits illumination light.

A hole is formed in the axial direction of the insertion portion 32 on the upper side of the hard tip member made of metal or the like in the tip portion 3]C of the insertion portion 32, and the lens frame 37 is fitted and fixed in the hole. ing. On the inner periphery of the front end of this lens frame 37, an ion exchange layer 38a is provided as in the first embodiment described above.

A (objective) cover glass 39 provided with the ion exchange layer 38b is fixed so as to close the objective window portion so that the front end surface that becomes the ion exchange layer 38a protrudes slightly forward of the surrounding front end surface, and the cover glass An objective lens 4o is disposed in contact with the rear end surface of the lens 39, and an objective lens 42 is disposed behind it via a spacing ring 41.

These objective lenses 40 and 42 connect an image guide fiber 43 serving as an image transmission means to a flexible tubular member 44 such that its distal end faces the position where an optical image of the object in front of the cover glass 39 is formed. It is pushed inside. The distal end of this tubular member 44 is fixed to the inner periphery of the hole on the rear end side of the distal end member 36 via a hard annular member 45 ◎Meanwhile, the lower part adjacent to the hole formed on the upper side of the distal end member 36 A hole is also formed on the side, and a cover glass 47 on which ion exchange layers 46a and 46b are formed is fitted and fixed at the front end of the hole so that the front end surface slightly protrudes forward. . A light guide fiber 48 is inserted through the cover glass 47 so that its front end surface (tip end surface) is in contact with the rear end surface of the cover glass 47 .

The distal end side of the light guide fiber 48 is fixed to the inner periphery of the hole on the lower side via an annular member guide, and the annular member 48
' A light guide fiber is housed at the rear end side, and the distal end side of a flexible tube member 49 that is inserted through the insertion section 32 is fixed. A curved section is installed at the rear part adjacent to the distal end part A. is formed, and a bending operation lever 51 provided on the operation section 33
By operating the insertion section 32.

The bending section force is applied to the left desk through an operating wire inserted into the operating section, so that the observation direction of the objective optical system disposed in the front part of the bending section can be varied. ing.

The corners of the front end surfaces of the cover glasses 39 and 47, which are fixed by closing the objective and illumination windows and protrude slightly forward from the front end surface of the tip member, are each edged in a tapered shape. is almsgiving.

According to the second embodiment of the present invention configured in this manner, the front end surfaces of each cover glass 39 and 47 are fixed so as to slightly protrude forward, and the surface layer of the protruding portion is a reinforcing layer. Since it is solid, there is almost no damage that occurs in the conventional example.

Therefore, safety can be improved as in the first embodiment.

Note that the end surface of the light guide fiber 17 in the first embodiment can also be sealed with a cover glass having an ion exchange layer formed thereon, so that the end surface of the light guide fiber 17 is less likely to be damaged.

Further, the cover glasses 19, 39, 47 on which the ion exchange layer is formed according to the present invention can also be applied to cover glasses for sealing the eyepiece side window.

Ion exchange layers 27a, 27b; 3 in the above
8a.

The cover glasses 19, 39, etc. on which the cover glasses 38b, etc. are formed are not limited to those in which the end faces facing the outside protrude or are fixed flush with each other, but the present invention also applies to cases in which they are fixed so as to form four parts. It is a season that falls into the category of. In this case, in order to avoid forming a step-like recess, it is preferable to form the portion around the cover glass so as to widen in a tapered shape toward the outside.

The ion-exchange reinforcing layer may not only be formed on both sides as in each of the above-mentioned embodiments, but may also be formed on at least the end face facing the outside. good.

In the case of ion exchange, the strength is enhanced by replacing with alkali ions having a large ionic radius, but it goes without saying that the present invention is also effective when replacing with alkali ions having a small ionic radius.

Further, although the above description is directed to the endoscopes 11 and 31 for direct viewing, the present invention can be similarly applied to oblique view type and side view type endoscopes.

Note that the present invention is not limited only to the above-mentioned cases,
An endoscope that is provided with a cover glass provided with an ion exchange layer on at least one of the objective side window, eyepiece side window, and illumination side window in the observation optical system falls within the scope of the present invention. .

As described above, according to the present invention, since the cover glass trap ion exchange layer is formed to be closed by a transparent member having an opening for observation or illumination, the strength is increased and the cover glass is not damaged. This has the advantage of suppressing the occurrence of accidents and improving safety.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a part of the distal end of the insertion section in a conventional example, FIGS. 2 and 3 relate to the first embodiment of the present invention, and FIG. FIG. 3 is an enlarged sectional view showing a part of the distal end of the insertion portion in FIG. 2, and FIGS. 4 and 5 relate to the second embodiment of the invention; The figure is a perspective view showing the flexible endoscope of the second embodiment, and FIG. 5 is an enlarged side view showing the distal end side of FIG. 4 with a portion cut away. DESCRIPTION OF SYMBOLS 11... Rigid endoscope 12, 32... Insertion part 15, 41... Eyepiece part 17, 47...
・Light guide fiber 19, 39
, 47...Cover glass 21,
22, 24, 40, 42...objective lens
27a, 27b, 38a, 38b, 46a. 46b...Ion exchange layer 31...Flexible endoscope 3
5...-Tip 43...Image guide fiber も-“knee/’

Claims (1)

[Claims] (1) The object illuminated by the illumination light emitted from the illumination window is imaged by the objective optical system in the objective window,
In an endoscope configured to allow observation from behind the eyepiece window, at least one of the illumination window, objective window, and eyepiece window is closed with a cover glass on which an ion exchange layer is formed. An endoscope with a reinforced cover glass characterized by: (:2) The ion exchange layer is formed by replacing a glass member containing alkali ions with alkali ions having a larger or smaller ionic radius than the alkali ions. An endoscope with a reinforced cover glass.