1. Field of the Invention
The present invention relates to an endoscope, particularly an endoscope having a characteristic distal end structure of its insertion unit.
2. Description of the Related Art
Conventionally, an endoscope has been widely used, for example, in a medical field. The endoscope, for example, can provide observation of organs within a body cavity by inserting an elongated insertion unit into the body cavity and various treatments using a treatment instrument inserted into a treatment instrument insertion channel as necessary. A bendable portion is formed at the distal end of the insertion-unit, and the observation direction of an observation window at the distal end can be changed by operating an operation unit of the endoscope.
The conventional endoscope has a viewing angle of, for example, 140 degrees, and an operator observes a body cavity with an observation image at the viewing angle; when the operator wishes to observe a part outside the field of view during the observation of the body cavity, the part outside the field of view can be observed by bending the bendable portion. The endoscope having the viewing angle has two illumination windows at the distal end of the insertion unit, and illumination through the two illumination windows has been sufficient for the viewing angle.
On the other hand, in order to maximize the range of observation, an endoscope with a wider range of the viewing angle (see Japanese Patent Application Laid-Open No. H04-102432, for example) has been proposed. At the distal end of the insertion unit, plural illumination windows illuminate the object in order to secure the wide field of view and to prevent an observation image displayed on a monitor from losing the quantity of light at a surrounding area thereof.
Also, the endoscope has a variety of functions, especially a function to clean the observation window with a water feeding nozzle, wherein in general, the water feeding nozzle is provided to project a portion thereof from the surface of the distal end.
When the viewing angle is widened, illumination which illuminates the wider range of area is necessary, and therefore three or more illuminating units are preferably used. However, if three or more illuminating units are mounted, the illumination light hits the water feeding nozzle, thereby giving a tendency to cause flare in the observation image due to the reflection light from the surface of the water feeding nozzle and giving a difficulty in obtaining the clear observation image.
An endoscope according to one aspect of the present invention has an insertion unit and is used for an endoscope apparatus which displays an observation image obtained by an imaging device. The endoscope includes an observation window provided on an end surface of a distal end portion of the insertion unit to introduce a reflecting light from an object to the imaging device; a plurality of illuminating units, for emitting illumination light for illuminating the object, provided around the observation window at the end surface of the distal end portion; and a water feeding nozzle, for feeding liquid to a surface of the observation window, provided on the end surface of the distal end portion of the insertion unit. An axis substantially positioned at a center of an illuminating range of the illuminating unit is inclined in a direction away from a distal end of an observing direction of an optical axis of an observation optical system including the observation window, with respect to the optical axis of the observation optical system, so that the illumination light emitted from the plurality of illuminating units does not hit the water feeding nozzle.
An endoscope according to another aspect of the present invention has an insertion unit and is used for an endoscope apparatus which displays an observation image obtained by an imaging device. The endoscope includes an observation window provided on an end surface of a distal end portion of the insertion unit to introduce a reflecting light from an object to the imaging device; a plurality of illuminating units, for emitting illumination light for illuminating the object, provided around the observation window at the end surface of the distal end portion; and a water feeding nozzle, for feeding liquid to a surface of the observation window, provided on the end surface of the distal end portion. The end surface of the distal end portion has a flat top and a slope which inclines while extending backward from the top, the observation window and the water feeding nozzle are provided at the top, and the plurality of illuminating units are provided along an inclination of the slope.
The above and other objects, features, advantages and technical and industrial significance of this invention will be better understood by reading the following detailed description of presently preferred embodiments of the invention, when considered in connection with the accompanying drawings.
Initially, according to
The endoscope 1 includes an operating unit 2 which performs bending operation and controls a channel system, an insertion unit 3 whose proximal end is connected to the operating unit 2 and which is inserted into the body cavity, and a universal cable 3a which is extended out from the operating unit 2 and has a connector portion 4 at its end. The connector portion 4 is connected to the light source 5 and the video processor 6 via a predetermined connector. The video processor 6 is connected to the monitor 7. The insertion unit 3 is provided with a flexible tube 8, a bendable portion 9 provided at the distal end side of the tube 8, and a distal end portion 10 provided at the distal end side of the bendable portion 9. The distal end portion 10 includes an imaging device 32d for obtaining an image of a region within the body cavity.
The image signal of the region within the body cavity obtained by the imaging device 32d positioned in the distal end portion. 10 is transmitted to the video processor 6 via the universal cable 3a. The vide processor 6 includes a signal process circuit (not shown in the figures) which processes the transmitted image signal, and based on the processed signal, displays the obtained observation image 7a of the region on the display screen of the monitor 7, which is a display unit connected to the video processor 6.
The operating unit 2 has an operating knob (not shown in the figures) for remotely bending the bendable portion 9. Operating the operating knob generates tensile and relaxation effects of an operating wire (not shown in the figures) inserted in the insertion unit 3, and as a result the bendable portion 9 can be bent in four directions.
As shown in
The end surface 21 is configured with a flat top 21a at a peak thereof and a tapered slope 21b which inclines from the top 21a so that a bottom thereof extends backward relative to the end surface 21, i.e., toward a proximal end of the insertion unit 3. The above-descried observation window 22 and the water feeding nozzle 25 are on the top 21a. In this case, the optical axis of a lens to be provided in the observation window 22 is substantially identical to an axis in a direction of a normal line of the flat surface of the top 21a and in a longitudinal direction of the channel of the water feeding nozzle 25. On the other hand, the above-described three illumination windows 23 are positioned at the tapered slope 21b along the inclination thereof, respectively. In this case, an axis which is substantially positioned in almost center of an illuminating area of the respective illumination light emitted from the three illumination windows 23 inclines in a direction to move apart from a point ahead in an observation direction of the optical axis, i.e., a point at the object side, with respect to the longitudinal direction of the channel of the water feeding nozzle 25 and the optical axis of the lens provided in the observation window 22. Also, the treatment instrument opening 24 and the forward water feeding nozzle 26 are positioned at the slope 21b so that the longitudinal direction of the respective channels thereof is substantially identical to the direction of the optical axis of the lens provided in the observation window 22.
A light guide unit 33 is comprised of the illumination window lens 33a and an optical fiber bundle 33b functioning as a light guide. The end of the optical fiber bundle 33b is fixed within a metal pipe 33c by adhesive agent, for example. The end of the optical fiber bundle 33b and the illumination window lens 33a are inserted into and fixed to a frame 33d. The light guide unit 33 is fixed to the distal end rigid portion 31 with a fixing screw 34. The proximal end of the metal pipe 33c and the optical fiber bundle 33b are covered by the flexible tube 33g, and further a portion of the metal pipe 33c and the tube 33g are covered by a covering tube 33e. The covering tube 33e is fixed to the metal pipe 33c with a bobbin winding 33f. The metal pipe 33c, as shown in
In addition, the illumination center axis is an axis substantially positioned in the center of the illuminating area of the illumination light emitted by an illumination unit including the later described LED; here, the illumination center axis is the optical axis of the optical system of, for example, the illumination window 23a included in the illumination unit.
The distal end of the water feeding nozzle 25 is provided with an opening 25a. The opening 25a is designed so that water ejected from the water feeding nozzle 25 is fed in a direction substantially parallel to a flat surface perpendicular to the optical axis 32LA of the imaging unit 32 and in a direction to pass through the surface of the observation window lens 32a at the observation window 22 and the surface of the illumination lens 33a at the illumination window 23a. The proximal end of the water feeding nozzle 25 is pipe-shaped and is connected to a water feeding tube 25c via a connecting tube 25b. Accordingly, the connecting tube 25b and the water feeding tube 25c constitute a water feeding tube channel. The water feeding tube 25c is fixed to the connecting tube 25b by the bobbin winding 25d.
The proximal end of the distal end rigid portion 31 is fixed to one portion of a curved top coma 35. The proximal end of the distal end rigid portion 31 and the curved top coma 35 are covered by the covering tube 36. The covering tube 36 is fixed to the distal end rigid portion 31 with the bobbin winding 37.
Next, the positional relationship between the observation window 22 at the distal end portion 10 and one illumination window of the three illumination windows 23 is explained next. As shown in
Furthermore, within the insertion unit 3, in addition to the imaging unit 32, the light guide of the optical fiber bundle corresponding to the three illumination windows 23 and the channel as a built-in component corresponding to the treatment instrument opening 24, the water feeding nozzle 25, and the forward water feeding nozzle 26 are inserted. As such, in addition to the imaging unit 32, six built-in components are positioned within the distal end portion 10, and the diameter of the distal end portion 10 needs to be kept from becoming large. Here, as shown in
Furthermore, as shown in
The imaging device 32d transmits the image signal to the video processor 6 by light obtained through the observation window 22; however, the video processor 6 performs the image processing on the image signal and generates the data of the observation image 7a of substantially rectangular in its shape. The substantially rectangular observation image 7a, as shown in
Next, the illuminating area of the illumination light from the illumination window 23 is explained. As shown in
Here, in order to avoid causing such reflection and to prevent the water feeding nozzle 25 from going in the illuminating area LW defined by the illumination angle θ1 of the illumination light from the illumination window lens 33a, the illumination center axis 33LA of the illuminating unit including the illumination window lens 33a is inclined with respect to the optical axis 32LA in a direction that the end of the illumination center axis 33LA is away from a distal end of the observation direction of the optical axis 32LA of the observation optical system including the observation window 22. As a result, the water feeding nozzle 25 is not included in the illuminating area LW, and the reflection of the illumination light does not occur on the surface of the water feeding nozzle 25, thereby preventing flare in the observation image as reflecting light hits the observation window 22.
Especially, as shown in
Similarly, the illumination light from the respective illumination window lenses provided in the illumination windows 23b, 23c is designed not to hit the water feeding nozzle 25 as well. That is, in order for the water feeding nozzle 25 not to be in the illuminating area defined by the illumination angles η2 and η3 (not shown in the figures) of the respective illumination light from the respective illumination window lenses provided in the illumination windows 23b, 23c, the respective illumination center axes by the respective illuminating units including the respective illumination window lenses provided in the illumination windows 23b, 23c is inclined with respect to the optical axis 32LA of the observation optical system including the observation window lens 32a in the direction to move apart from a distal end of the observation direction. At this time, the illuminating area of the respective illumination light emitted from the illumination window lens of the illumination window 23b and the illumination lens of the illumination window 23c having the inclination angles θ21 and θ31 (not shown in the figures) relative to the surface of the observation window lens 32a respectively is an area that does not cover the water feeding nozzle 25.
Accordingly, there is no chance that all illumination light of the three illumination windows 23 hits the water feeding nozzle 25 and the reflection light goes in the observation window 22, thereby obtaining a clear observation image without flare, and the distance between the illumination window 23 and the water feeding nozzle 25 does not need to be reserved excessively so as to avoid flare, thereby enabling to minimize the size of the distal end portion 10.
Also, in the above-explanation, an example employing the light guide unit including the illumination window unit and the like was explained as the illumination means; however, a light emitting diode (LED) can be used on the end surface 21 of the distal end portion 10 as a light emitting element. At that time, plural LEDs can be arranged along the inclination of the slope 21b of the end surface 21, and the illumination center axis of the respective LEDs is positioned in the direction to move apart from a distal end of the observation direction of the optical axis of the observation optical system and is inclined with respect to the optical axis of the observation optical system.
Also, in the above-example, the example with three illuminating units provided therein was explained because this example provides advantages in illuminating sufficient amount of light to the object even with three illuminating units and in-addition reducing the outside diameter of the distal end comparing to the case when four or more illuminating units are provided.
On the other hand, as ejecting water, i.e., liquid, from the opening portion 25a of the water feeding nozzle 25, an object such as fouling adhered on the surface of the observation window lens 32a provided in the observation window 22 needs to be removed. This is because when the insertion unit 3 of the endoscope 1 is inserted in the body cavity, the object such as fouling adheres on the surface of the observation window lens 32a.
However, even though JP-A No. H04-102432 (KOKAI) discloses the endoscope having a wide viewing angle, water from the water feeding nozzle disclosed in
Here, in the present embodiment, the observation window 22 and the illumination window 23a are provided at the top 21a of the end surface 21 and the surrounding surface of the observation window 22 has a plane shape as described above. Concretely, as shown in
Also, the distal end portion 10 of the endoscope 1 is preferably narrower in consideration of insertability and pain to the patients.
The observation window 22, three illumination windows 23, and the treatment instrument opening 24, and the water feeding nozzle 25 are provided at the end surface 21 of the distal end portion 10. However, as shown in
As shown in
Furthermore, at this time, the built-in component such as the optical fiber bundle corresponding to the illumination window 23c may not fit in the dashed line circle. In such a case, the cross section shape of the distal end portion 10 from the end surface 21 of the distal end portion 10 to a position slightly apart toward the proximal end, i.e., a position where the built-in component such as the optical fiber corresponding to the illumination 23c fits in the predetermined circle in the dashed line, has the projection at one portion thereof.
By making this cross section shape, the diameter of the distal end portion 10 can be reduced, thereby improving the insertability of the insertion unit and relieving the pain of the patients.
The above-explanation illustrates, in
Next, a method of forming the light guide in the manufacturing process of the above-described insertion unit 3 will be explained. As explained in
The three optical fiber bundles with the bent ends are bundled into one within the insertion unit 3 and are connected to the light source 5.
The end side of each optical fiber bundle is formed by binding the same by the adhesive agent. Here, when the end of the respective optical fiber bundle is formed by the adhesive agent, as shown in
However, if the end side portion of the three optical fiber bundles 51 are formed by bending in the same direction as shown in
Then, as shown in
Furthermore, after manufacturing the endoscope 1, for example, when inspecting the same, there is a chance where only the imaging unit 32 needs to be replaced because of failure. However, as described above, when the imaging unit 32 is fixed in the distal end rigid portion 31 by filling the filler such as silicon rubber in the distal end rigid portion 31, the imaging unit 32 cannot be removed alone from the distal end rigid portion 31 practically.
Then, as shown in
As shown in
As such, within the distal end rigid portion 31, the masking film 61 is positioned around the imaging unit 32, and if only the imaging unit 32 is attempted to be pulled out from the distal end rigid portion 31, only the imaging unit 32 wrapped inside the masking film 61 can be pulled from the distal end rigid portion 31 together with the masking film 61 or as being peeled from the masking film 61 because of the existence of the masking film 61.
Accordingly, even if the filler such as silicon is filled in the distal end rigid portion 31 to fix the imaging unit 32 at the distal end rigid portion 31, only the imaging unit 32 can be taken from the distal end rigid portion 31.
As such, according to the embodiments of the present invention, even if the endoscope has three illumination windows, light from the three windows is distributed with good balance, thereby realizing the endoscope with excellent observability.
Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.
Number | Date | Country | Kind |
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2003-412613 | Dec 2003 | JP | national |
This application is a continuation of PCT international application Ser. No. PCT/JP2004/017462 filed Nov. 25, 2004 which designates the United States, incorporated herein by reference, and which claims the benefit of priority from Japanese Patent Application No. 2003-412613, filed Dec. 10, 2003, incorporated herein by reference.
Number | Date | Country | |
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Parent | PCT/JP04/17462 | Nov 2004 | US |
Child | 11450809 | Jun 2006 | US |