JP4633281B2 - Endoscope - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an endoscope provided with a field mask for field stop.
[0002]
[Prior art]
Conventionally, by inserting a long and thin insertion portion into a body cavity, the inside of a body cavity can be observed, and various medical treatments can be performed using a treatment instrument inserted into a treatment instrument channel as necessary. Endoscopes are widely used. Also in the industrial field, industrial endoscopes that can observe and inspect internal scratches and corrosion of boilers, turbines, engines, chemical plants, and the like are widely used.
[0003]
In addition, an optical image formed by the objective optical system is transmitted to the endoscope by an image guide to the eyepiece, and the observer's eye is brought close to the back of the eyepiece optical system provided in the eyepiece. There are things that can be observed. This eyepiece optical system was composed of an eyepiece lens system for magnifying and observing the optical image transmitted by the image guide, and a field stop provided with an index for setting the field range and displaying the field direction. . This field stop is disposed in the vicinity of the final transmission surface of the image guide.
[0004]
In addition, for example, Japanese Utility Model Publication No. 2-28491 discloses an endoscope in which a function of this index is improved in an endoscope having a projecting index that displays a direction or the like in a visual field observed from the rear of the eyepiece. An endoscope field stop device is shown.
[0005]
[Problems to be solved by the invention]
However, when a field mask having a hollow field portion is arranged as in the field stop device for an endoscope disclosed in Japanese Utility Model Publication No. 2-28491, it is difficult to form the thickness of the field mask to 30 μm or less. . Therefore, the distance from the eyepiece side to the image guide final transmission surface to which the optical image formed by the objective optical system is transmitted, and the distance from the eyepiece side to the field mask end surface that forms the boundary of the field of view range Is different. For this reason, when focusing on the observation optical image on the final transmission surface, the focal length with respect to the boundary forming portion of the field mask does not match, and the boundary portion of the field mask is blurred. Further, when the field mask is formed thin, there is a problem that physical strength is lowered.
[0006]
Also, when the field mask is formed of phosphor bronze, when forming the hollow field part of this field mask, the feature is that the ridge line part between the inner surface of the hollow field part and the inner surface of the other hollow field part is rounded. Have. For this reason, the index formed on the visual field mask is also rounded.
[0007]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a field mask having high physical strength and no roundness in an index, in which blurring at the boundary is eliminated.
[0008]
[Means for Solving the Problems]
The endoscope of the present invention is disposed at the distal end portion of the endoscope insertion portion, and has an objective optical system that forms an optical image, and an optical image formed by the objective optical system based on the endoscope insertion portion. An image guide that transmits to the end, an eyepiece optical system that is disposed at the proximal end of the endoscope insertion portion and that magnifies the optical image transmitted by the image guide, and an eyepiece optical system side end surface of the image guide In an endoscope provided with a field mask having a hollow field portion that is provided and regulates an observation range of the optical image,
The field mask can be set to a thickness within a range of 1 μm to 30 μm, and a thin member formed with a hollow field portion disposed on the image guide side, and the thin field member integrated with the thin field member than the hollow field portion. It has a large through-hole and a thick member that is thicker than the thin member .
[0009]
According to this configuration, by using an SOI wafer or an organic coating (polyimide) as a thin member, the thickness of the field mask is 30 μm or less, and the field mask and the final transmission surface on which the optical image of the image guide is transmitted. The difference in distance is minimized and the focus shift decreases.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
1 and 2 relate to a first embodiment of the present invention. FIG. 1 is a diagram illustrating a schematic configuration of an endoscope, and FIG. 2 is a diagram illustrating a field mask. 2A is a front view of the field mask, and FIG. 2B is a cross-sectional view taken along the line AA in FIG. 2A.
[0011]
As shown in FIG. 1, an endoscope 1 according to this embodiment includes, for example, an endoscope insertion portion (hereinafter abbreviated as an insertion portion) 2 that is inserted into a body cavity and a distal end side of the insertion portion 2. A distal-end component 3 having an objective lens 3a constituting the objective optical system, an eyepiece 4 constituting an eyepiece optical system provided on the proximal end side of the insertion portion 2, and a hollow field portion to be described later are formed. It is mainly composed of an eyepiece unit 6 on which a field mask 5 is arranged.
[0012]
An image guide 7 composed of an optical fiber bundle is inserted through the insertion portion 2. One end surface of the image guide 7 is disposed to face the objective lens 3 a, and a field mask 5 is disposed on the optical image final transmission surface which is the other end surface to face the eyepiece lens 4. This field mask 5 uses a Silicon On Insulator Wafer (hereinafter abbreviated as SOI wafer), is excellent in heat resistance and moisture resistance, and has a higher hardness than a field mask formed of phosphor bronze, for example.
[0013]
2A and 2B, the field mask 5 includes, in order from the optical image final transmission surface side of the image guide 7, an active layer 11 that is an SOI wafer made of silicon, which is a thin member, and silicon. It is composed of three layers: a bonding layer 12 made of the above oxide and a substrate 13 made of silicon which is a thick member.
[0014]
That is, the field mask 5 is formed by combining a silicon oxide film to be the bonding layer 12 provided on one surface of the active layer 11 and a silicon oxide film to be the bonding layer 12 provided on one surface of the substrate 13. In this state, it is formed by mechanical joining in high heat.
[0015]
The thickness of the active layer 11 is in the range of 1 μm to 30 μm. A hollow visual field portion 11 a serving as a boundary portion is formed in the central portion of the active layer 11. An index 11b configured as a wedge-shaped protrusion for determining the front and back surfaces and the positional relationship with respect to the optical image formed by the objective optical system protrudes from the hollow field portion 11a. By providing the index 11b, the hollow visual field portion 11a is asymmetrical in the vertical and horizontal directions to clarify the positional relationship with respect to the optical image.
[0016]
The hollow visual field 11a and the index 11b are formed by linear etching using high-density plasma inductive coupled plasma etching (hereinafter abbreviated as ICPE) or reactive lon etching (hereinafter abbreviated as RIE). The edge portion is not rounded, and in particular, the ridge line portion between one inner surface of the hollow visual field and the other inner surface of the hollow visual field, such as phosphor bronze, is not rounded. In the present embodiment, the thickness of the active layer 11 is about 10 μm.
[0017]
On the other hand, the thickness of the substrate 13 is thicker than the thickness of the active layer 11. A window portion 13a larger than the outer shape of the hollow visual field portion 11a is formed in the central portion of the substrate 13. A concave auxiliary indicator 13b for determining the front and back and the mounting direction is formed on the substrate surface.
[0018]
Thereby, the difference between the distance to the optical image final transmission surface of the image guide 7 and the distance to the side surface of the eyepiece of the active layer 11 that forms the boundary portion of the field mask 5 is very small.
[0019]
Thus, since the thickness of the active layer using the SOI wafer as the field mask is thinner than the thickness of the field mask using phosphor bronze, the distance to the optical image final transmission surface of the image guide, and the active layer Because the difference from the distance to the eyepiece lens side is minimal, when focusing on the optical image of the final transmission surface of the optical image of the image guide, the focus shift at the boundary forming the hollow field of the field mask This can reduce the blur of the field mask.
[0020]
In the field mask using the SOI wafer, since the hollow field portion of the active layer is formed by ICPE, the index edge can be made clear without being rounded.
[0021]
Furthermore, the field mask using the SOI wafer is excellent in heat resistance and moisture resistance, so that it is possible to surely prevent the deformation due to heat and the rust due to moisture, and compared to the field mask using phosphor bronze. Since the hardness is high, when the field mask is gripped with tweezers during the field mask mounting operation, the field mask can be easily mounted without bending the field mask. In this embodiment, the field mask is formed integrally with the active layer on the substrate formed thicker than the active layer, thereby further improving the physical strength and further improving the workability of mounting the field mask. be able to.
[0022]
Also, by visually recognizing the position of the auxiliary index provided on the field mask, the front and back of the field mask and the mounting direction can be determined without observing the index under a microscope. This further improves the workability of attaching the visual field mask.
[0023]
In the field mask 5 of this embodiment, the active layer 11 and the substrate 13 are integrated with the bonding layer 12, but the field mask 5 may be formed only with the thin active layer 11. However, in this case, physical strength is inferior to that of a field mask in which the substrate 13 is integrated, so that care must be taken when handling the field mask.
FIG. 3 is a view for explaining another configuration of the field mask according to the second embodiment of the present invention.
3A is a front view of a visual field mask in which polyimide is formed on the surface of a substrate made of silicon, and FIG. 3B is a cross-sectional view taken along the line BB of FIG.
[0024]
In this embodiment, as shown in FIGS. 3A and 3B, the field mask 5A is provided on one surface side of the substrate 21 made of silicon which is a thick member, for example, a thin film layer of polyimide which is an organic film as a thin member. 22 is formed into a film.
[0025]
The thin film layer 22 has a thickness in the range of 1 μm to 30 μm, preferably about 5 μm. The polyimide forming the thin film layer 22 is cured while shrinking after film formation, and the stress on the substrate 21 is stabilized in a completely cured state, thereby improving the physical resistance of the substrate 21. That is, by providing the substrate 21 made of silicon on the thin film layer 22 made of polyimide, the physical resistance of the field mask 5A is greatly improved over the physical resistance of the field mask in the case of being composed of polyimide alone.
[0026]
In addition, the said board | substrate 21 is the same structure as the board | substrate 13 of the said 1st Embodiment, and has the window 21a and the auxiliary | assistant parameter | index 21b. The thin film layer 22 also has a hollow field portion 22a substantially the same as the active layer 11 in the first embodiment, and the hollow field portion 22a discriminates the front and back of the optical image formed by the objective optical system and the positional relationship. An index 22b made of a wedge-shaped protrusion is provided. In this embodiment, since the hollow visual field 22a provided with the index 22b is formed by RIE, the edge is not rounded. Other configurations are the same as those of the first embodiment.
[0027]
As described above, the field mask formed by providing the polyimide thin film layer on the substrate has an extremely thin thickness compared to the thickness of the field mask using phosphor bronze. In addition, when the optical image on the final transmission surface of the optical image of the image guide is brought into focus, the blur of the field mask can be eliminated.
[0028]
In addition, since the field mask using polyimide is formed by forming the hollow field part in the thin film layer by RIE, the edge of the index is not rounded on the ridge line part between one surface and the other surface like phosphor bronze. It can be clarified without being rounded.
[0029]
Furthermore, since the field mask using polyimide uses polyimide at a portion that limits the field of view range, the processing cost is low.
[0030]
In addition, since polyimide cures while shrinking after film formation, the stress on the substrate can be stabilized in a completely cured state, and the physical resistance of the substrate can be improved. In addition, since polyimide is plastic, thin film The layer is difficult to break. By these things, the operation | work at the time of visual field mask mounting | wearing can be performed easily.
[0031]
Further, by forming a polyimide film on a substrate made of silicon, the physical resistance of the visual field mask is improved over the physical resistance of the visual field mask composed of a single polyimide, and the work when the visual field mask is mounted can be easily performed.
[0032]
In the above-described embodiment, the thick member is not limited to the silicon substrate, and a transparent optical member such as sapphire glass may be used. This eliminates the need to provide a window on the thick member.
[0033]
It should be noted that the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention.
[0034]
[Appendix]
According to the embodiment of the present invention as described above in detail, the following configuration can be obtained.
[0035]
(1) An objective optical system that is disposed at the distal end portion of the endoscope insertion portion and forms an optical image, and transmits the optical image formed by the objective optical system to the proximal end portion of the endoscope insertion portion. An image guide, an eyepiece optical system disposed at a proximal end portion of the endoscope insertion portion and enlarging an optical image transmitted by the image guide, and provided on an eyepiece optical system side end surface of the image guide; In an endoscope comprising a field mask having a hollow field portion that regulates the observation range of an image,
An endoscope in which the field mask is formed of a thin member whose thickness can be set within a range of 1 μm to 30 μm.
[0036]
(2) The field mask has a thin member formed with a hollow field portion disposed on the image guide side, and has a through hole larger than the hollow field portion integrally formed with the thin member, than the thin member. An endoscope comprising a thick and thick member.
[0037]
(3) The endoscope according to appendix 1 or appendix 2, wherein the thin member is silicon.
[0038]
(4) The endoscope according to appendix 1 or appendix 2, wherein the thin member is polyimide.
[0039]
(5) The endoscope according to appendix 2, wherein the thin member is an organic coating.
[0040]
(6) The field mask according to item 2, wherein the field mask includes a substrate made of silicon, a bonding layer made of silicon oxide provided on one surface of the substrate, and an active layer provided on the other surface of the bonding layer. Endoscope.
[0041]
(7) The endoscope according to appendix 6, wherein the active layer is an SOI wafer.
[0042]
(8) The endoscope according to appendix 2, wherein the visual field mask is configured by forming a thin film layer made of polyimide on a substrate made of silicon.
[0043]
(9) The endoscope according to appendix 1 or appendix 2, wherein the hollow field portion of the thin member is formed by dry etching. (10) appendix 1 or appendix 2, wherein the hollow field portion of the thin member is formed by inductive coupled plasma etching. Endoscope.
[0044]
(11) The endoscope according to appendix 1 or appendix 2, wherein the hollow visual field portion of the thin member is formed by reactive lon etching.
[0045]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a visual field mask that is free from blurring at the boundary, has a high physical strength, and has no rounded index.
[Brief description of the drawings]
FIG. 1 and FIG. 2 relate to a first embodiment of the present invention, FIG. 1 is a diagram for explaining a schematic configuration of an endoscope, and FIG. 2 is a diagram for explaining a field mask. The figure explaining other composition of the field mask concerning a 2nd embodiment.
DESCRIPTION OF SYMBOLS 1 ... Endoscope 5 ... Field mask 6 ... Eyepiece part 11 ... Active layer 11a ... Hollow field part 11b ... Index 12 ... Bonding layer 13 ... Substrate 13a ... Window part

Claims (4)

An objective optical system that is disposed at the distal end of the endoscope insertion portion and forms an optical image; and an image guide that transmits the optical image formed by the objective optical system to the proximal end portion of the endoscope insertion portion; An eyepiece optical system which is disposed at a proximal end portion of the endoscope insertion portion and expands an optical image transmitted by the image guide; and provided on an eyepiece optical system side end surface of the image guide, and observes the optical image. In an endoscope comprising a field mask having a hollow field part for regulating a range,
The field mask can be set to a thickness within a range of 1 μm to 30 μm, and a thin member formed with a hollow field portion disposed on the image guide side, and the thin member integrally with the thin field member than the hollow field portion. An endoscope having a large through hole and a thick member thicker than the thin member . The thick member is a substrate made of silicon, and further has a bonding layer made of silicon oxide provided on one surface of the substrate, and the thin member is an active layer provided on the other surface of the bonding layer. The endoscope according to claim 1, wherein the endoscope is a layer. The endoscope according to claim 1, wherein the thin member is silicon or polyimide. The endoscope according to claim 2, wherein the active layer is an SOI wafer.

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