JPS62133415A - Visual field converter for endoscope - Google Patents

Abstract

PURPOSE:To convert exactly and smoothly the visual field of an endoscope by forming a driving member for turning a visual field converting member by a shape memory material and changing the form by heating to turn the visual field converting member. CONSTITUTION:Since a wire 11 is not heated because no current flows into the wire 11 under the state that a switch of a current supply part 14 is opened, the wire 11 is kept at short state (length l'), a mirror 8 is made approximately parallel with the optical axis of an objective lens 6 as shown by a broken line and the forward field can be observed through a direct observation window 18. When the switch 17 is closed, current is supplied to the wire 11, the wire 11 is heated by Joule heat generated from itself and turned to long state (length l). When the wire 11 is extended, a lever 9 and the mirror 8 are turned around a shaft 7 in the clockwise direction and the reflecting surface of the mirror 8 is inclined by 45 deg. e.g. from the optical axis of an objective lens 6. Consequently, a light beam passed through a side observing window 19 is reflected by the mirror 8 and made incident upon the objective lens 6, so that the side can be observe.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to an endoscope visual field conversion device that converts the visual field direction of an endoscope. [Problems to be solved by conventional techniques and inventions] In recent years,
Inserting a long and thin insertion part into a body cavity to observe the inside of the body cavity,
Medical endoscopes, which can perform treatments and other treatments using various treatment instruments, and industrial endoscopes, which can be inserted into pipes, etc., to inspect and treat the insides, are widely used. It is being By the way, this endoscope, for example, is inserted into a body cavity, irradiates illumination light toward a target part in the body cavity, forms an image of the reflected light from the target object with an objective lens, and passes it through an image guide fiber or the like. The image is transmitted to the eyepiece so that objects can be visually observed. Therefore, depending on the object to be observed, it is necessary to change the viewing direction. Therefore, conventionally, as shown in Japanese Utility Model Publication No. 54-10794, the field of view is A scheme d has been proposed to perform the conversion. However, with conventional devices, the insertion section of the endoscope is If the operation wire is long or has many bends in the insertion section, the operation wire may become slack within the insertion section, and the drive of the operation wire in the operation section will not be completely transmitted to the prism or mirror placed in front of the objective lens. As a result, the rotation of prisms, mirrors, etc. becomes incomplete, and there is a problem that sufficient visual field conversion is not performed. Furthermore, since the operating wire is moved in the axial direction within the bent insertion section, there is a problem that resistance is large and visual field conversion cannot be performed smoothly. [Purpose of the Invention] The present invention has been made in view of the above-mentioned circumstances, and allows for reliable and smooth insertion of an endoscope even when the insertion section of the endoscope is long or has many bends. It is an object of the present invention to provide a visual field conversion device for an endoscope that can convert the visual field.

[Means and operations for solving the problems] The field-of-view conversion device for an endoscope according to the present invention includes a field-of-view conversion member rotatably provided in a part of the insertion portion of the endoscope.
A driving member made of a shape memory material for rotating the visual field conversion member and a heating means for heating the driving means are provided.
! It's ours. That is, by being heated by the heating means, the driving member made of the shape memory material changes its shape and rotates the visual field converting member, thereby converting the visual field. [Embodiments of the Invention] The present invention will be described in detail below with reference to the drawings. 1 and 2 relate to a first embodiment of the present invention, in which FIG. 1 is a cross-sectional view of the distal end of an endoscope, and FIG. 2 is a cross-sectional view of essential parts of the distal end of the endoscope. An insertion section 1 of an endoscope is provided with a distal end frame 2 on the distal end side, and a distal end main body 3 is housed within the distal end frame 2. The distal end of an image guide 4 made of an optical fiber bundle inserted into an endoscope is fixed in the distal end main body 3 via a fixing tube 5, and an objective lens is mounted opposite the distal end surface of the image guide 4. 6
is provided to form an observation image on the distal end surface of the image guide 4. Further, in front of the objective lens 6 of the tip body 3, a mirror 8 and a lever 9 are provided which rotate integrally around an axis 7, and this mirror 8 is parallel to the optical axis of the objective lens 6. It is rotatable from this position to a position where the reflecting surface faces the objective lens 6 at a predetermined angle with respect to the optical axis of the objective lens 6, for example, 45 degrees. Further, the tip frame 2 has a direct viewing observation window 18 at the tip.
A side viewing observation window 19 is provided on the outer peripheral surface through which the optical axis of the objective lens 6 passes when the mirror 8 is tilted by 45 degrees. When the mirror 8 is in a position parallel to the optical axis of the objective lens 6, the light incident from the direct viewing observation window 18 directly enters the objective lens 6, the front is observed, and the mirror 8 When the camera is tilted at a position facing the objective lens 6, the light incident from the side viewing observation window 19 is reflected by the mirror 8 and enters the objective lens 6, so that the side can be observed. There is. Further, a projecting piece 10 is provided on the outer peripheral surface of the tip body 3 and behind the lever 9. Therefore, between the lever 9 and the protruding piece 1o, there is a Ti-Ni or C
A wire 11 made of a shape memory □ alloy such as a u-Zn-AN alloy is stretched. In addition, when the lever 9 and the protruding piece 10 are conductive, the wire 11
As shown in FIG. 2, it is fixed to the lever 9 and the protruding piece 10 via a ring 12 made of electrically insulating resin or ceramic. In the shape memory alloy, when the martensitic phase (low temperature side) reversely changes to the austenite phase (0 side), the deformed martensitic phase returns to the original shape memorized by the austenite phase. It is something to return to. The shape memory alloy used in the present invention is bidirectional, not only remembering the shape in the austenite phase but also in the martensitic phase, and the shape reversibly changing according to temperature changes. It changes. The shape of the wire 11 is memorized so that it is short (length 1') on the low temperature side and long (length jI) on the high temperature side. On the other hand, lead wires 13 inserted into the endoscope are electrically connected to both ends of the wire 11, and the proximal end of the lead wire 13 is connected to an operation part (not shown) on the proximal side. It is connected to a current supply section 14 provided. The current supply section 14 includes, for example, a power source 15, a variable resistor 16, and a switch 17. Next, the operation of the endoscope visual field conversion device configured as described above will be explained. When the switch of the current supply section 14 is open, the wire 1
Since no current flows through wire 1 and wire 11 is not heated,
In the short state (length 1'), the mirror 8 is approximately parallel to the optical axis of the objective lens 6, as shown by the broken line. Thereby, the front can be observed through the direct viewing observation window 18. On the other hand, when the switch 17 is closed, the wire 11 is energized, heated by the Joule heat generated by itself, and changes to a shape on the high temperature side, that is, a long state (length 1). By extending the wire 11, the lever 9 and the mirror 8 are rotated clockwise about the axis 7, and the reflective surface of the mirror 8 is tilted, for example, by 45 degrees with respect to the optical axis of the objective lens 6. As a result, the light passing through the side-viewing observation window 19 is transmitted to the mirror 8.
Since the light is reflected by the object and enters the objective lens 6, it is possible to observe the side. As explained above, according to this embodiment, the current supply unit 1
By operating the switch 17 of 4 [17tlrJ], the field of view of the endoscope is switched between direct view and side view. Note that in this example, the wire 1 made of a shape memory alloy
1 was memorized so that it was short on the low temperature side and long on the high temperature side, but conversely, it may be made to be long on the low temperature side and short on the a-hot water side. Further, in this embodiment, the current supply section 14 is provided in the operation section of the endoscope, but it may be provided outside the endoscope. In addition, the shape memory alloy used as the drive member in this example has a temperature between the temperature at which the transformation starts and the temperature at which the transformation ends during the transformation from the austenite phase to the martensitic phase and vice versa. Its shape changes continuously according to changes. Therefore, the value of the current flowing through the wire 11 made of the shape memory alloy is controlled by the variable resistor 1.
6 to avoid changing the temperature of the wire 11 between the temperature at which the transformation starts and the temperature at which the transformation ends '/Q degrees, the length of the wire 11 can be changed continuously. The angle can also be changed continuously. Utilizing this, an observation window with an open field of view from direct view to side view is provided in the tip frame 2, and by controlling the resistance value of variable resistor 16, a continuous wide field of view is provided from direct view to side view. Conversion becomes possible. Note that the composition of the shape memory alloy used in this case is selected such that the difference between the start temperature and the end temperature of transformation is large. FIG. 3 is a sectional view of the distal end of the endoscope in the second example of the actual droplet of the present invention. In this embodiment, there are two bars 2 at both ends of the rotation range of the mirror 8.
0.21, and the driving member for rotating the mirror 8 is constituted by a spring 22 made of a shape memory alloy. Therefore, if the length of the spring 22 is, for example, 1' or less on the low temperature side,
By memorizing the shape so that it is 1 or more on the high temperature side, the mirror 8 can be positioned at a predetermined position regardless of the precision of the shape of the spring 22, and the field of view can be changed more reliably. can. Other functions and effects are similar to those of the first embodiment. FIG. 4 is a cross-sectional view of the distal end of an endoscope according to a third embodiment of the present invention. In this embodiment, the mirror 8 is connected to the shaft 23 via the shaft 23.
A wire 11 made of a shape memory alloy is stretched between one lower end of the mirror 8 and the protruding piece 10. In this embodiment, the shape of the wire 11 is memorized so that it is short on the low temperature side and long on the high temperature side, and the mirror 8 rotates in response to opening and closing of the switch 17, as in the first embodiment. The field of view can be switched between direct view and side view. Other functions and effects are similar to those of the first embodiment. FIG. 5(a) is a perspective view of a driving member in a third embodiment of the present invention, and FIG. 5(b) is a side view of FIG. 5(a). In this embodiment, two support frames 25 and 26 are used to support the mirror 8.
The driving member is made of a shape memory alloy. The support frames 25 and 26 are formed into a prismatic shape with a bent part,
The bottom parts 25a, 26a are fixed to the end frame of the endoscope, and the raised parts 25b, 26b are rotatable. The inner surfaces of the raised parts 25b and 26b are provided with four parts, and both ends of the mirror 8 are fitted into these recesses, so that the mirror 8 is supported. Lead wires 13 are electrically connected near both longitudinal ends of the support frames 25 and 26, and these lead wires are connected to a Wi current supply unit (not shown) as in the first embodiment. There is. The support frames 25 and 26 are made of a bidirectional shape memory alloy, and are designed so that, for example, they extend as shown by the broken lines on the low temperature side, and the raised parts 25b and 26b rise at a 45° angle on the high temperature side. The shape is memorized. Therefore, when the support frame 25.26 is not energized, the support frame 25.26 is extended, the mirror 8 becomes parallel to the optical axis of the objective lens (not shown), and the endoscope becomes capable of direct viewing. On the other hand, when the support frames 25 and 26 are energized, the support frames 25 and 26 are heated by Joule heat generated by themselves.
bend. As a result, the mirror 8 is tilted by, for example, 45 degrees with respect to the optical axis of the objective lens, and the endoscope becomes capable of side viewing. FIG. 6 is a perspective view of a driving member according to a fourth embodiment of the present invention. In this embodiment, the support base 27 that supports the mirror 8 is made of a shape memory alloy and is used as a driving member. The support stand 27 is formed into a plate shape with a bent part, and the bottom part 27
a is fixed to the distal end frame of the endoscope, and the raised part 27b is rotatable. A mirror 8 is bonded to the upper surface of this raised portion 27b. Further, lead wires 13 are electrically connected to the front and rear ends of the support base 27, respectively, and the lead wires 13 are connected to a current supply section (not shown). This support base 27 is made of a bidirectional shape memory alloy, and its functions and effects are similar to those of the third embodiment. In the embodiments described above, a mirror is used as the visual field conversion member, but a triangular prism, a roof prism, etc. may also be used. In addition, in the embodiment, power is directly supplied to the drive member made of a shape memory alloy, and the drive member is heated by the Joule heat generated by the drive member itself, but a heating member such as a positive temperature coefficient thermistor is installed near the drive member. The drive member may also be heated. Further, although the illumination system of the endoscope was not described in the embodiment, the entire field of view of the endoscope may be illuminated, or the present invention may be applied to the illumination system to illuminate the illumination direction. may be converted in the same way as the viewing direction. Further, in the embodiment, the field of view of the endoscope was switched between direct view and side view, but the present invention can also be applied to a perspective-viewing endoscope. Furthermore, the shape memory alloy that forms the drive member is not limited to shape memory alloys, but may also be other bidirectional shape memory materials, such as shape memory resins or mixtures of shape memory alloys and shape memory resins. It's okay. [Effects of the Invention] As described above, according to the present invention, the driving member for rotating the visual field conversion member is formed of a shape memory material, and the driving member is heated by the heating means to change its shape. As a result, the field of view conversion member is rotated, so that the field of view of the endoscope can be changed reliably and smoothly even when the insertion section of the endoscope is long or has many bends. I can do it.

[Brief explanation of drawings]

1 and 2 relate to a first embodiment of the present invention, in which FIG. 1 is a top view of the distal end of the endoscope, FIG. 2 is a sectional view of the main parts of the distal end of the endoscope, and FIG. The figure is part 2 of the present invention. FIG. 4 is a cross-sectional view of the endoscope tip according to the third embodiment of the present invention, and FIG. 5(a) is a cross-sectional view of the endoscope tip according to the third embodiment of the present invention. FIG. 5(b) is a side view of FIG. 5(a), and FIG. 6 is a perspective view of the driving member in the fifth embodiment of the present invention.

Claims (3)

[Claims] (1) In a visual field converting device for an endoscope having a visual field converting member rotatably provided in a part of the insertion portion of the endoscope, a drive member made of a shape memory material that rotates the visual field converting member; 1. A visual field conversion device for an endoscope, characterized in that a heating means for heating the drive member is provided. (2) The visual field conversion device for an endoscope according to claim 1, wherein the heating means comprises the driving member and a power supply means connected to the driving member and supplying power. (3) The endoscope visual field conversion device according to claim 1, wherein the heating means is a heating member provided in the vicinity of the driving member and separately from the driving member.