JP2013094259A - Endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endoscope which has a sufficiently narrow diameter and enables inside the body to be observed over a wide range from the front to the side, resulting in improvement in work efficiency of a surgery, and which has a simple optical system thereby being disposable.SOLUTION: An endoscope 1 with a built-in optical system includes a long-length body 11 to be inserted into a body cavity, and an imaging part 12 disposed at an end on the distal end side of the long-length body 11. The imaging part 12 includes: an imaging device 125 with an imaging surface 124 arranged along the longitudinal direction of the endoscope 1; an optical lens 127 whose light incident surface 126 is disposed obliquely to the longitudinal direction of the endoscope 1, and which forms images of observation ranges A-D on the imaging surface 124; and a diaphragm member 128 provided on the light incident surface 126 of the optical lens 127 and provided with a hole part 131 formed to causes light to be incident on the imaging surface 124.

Description

  The present invention relates to an endoscope.

  In recent years, in the medical field, observations, treatments, and treatments are performed by inserting an endoscope having an optical system at the tip into an observation target. Conventionally, in order to simplify surgery, there is a high need for an endoscope that is sufficiently thin in diameter and that allows observation of a side portion where a lesion exists while observing the advancing direction (front portion). As an endoscope as described above, for example, Patent Document 1 has a super-wide-angle lens for obtaining front and side image information at a distal end portion of an endoscope, and the obtained image is transmitted through an optical fiber. An endoscope that transmits to an image sensor disposed outside the endoscope is described. Further, Patent Document 2 includes a lens system composed of a plurality of lenses that exhibit the function of an ultra-wide-angle lens, and the lens system has a light incident surface that is oblique with respect to the longitudinal direction of the endoscope. There is described an endoscope that is arranged as described above and transmits an obtained image as it is to an image sensor via a relay lens.

Japanese Patent Laid-Open No. 10-290777 JP 2010-17552 PR

  Endoscopes are conventionally large in size and expensive due to the complexity of their optical systems. The endoscopes described in Patent Document 1 and Patent Document 2 also have a plurality of lens systems as an optical system, and send an image to an image sensor via an optical fiber or a relay lens. Big and expensive. In general, it is ideal for medical devices such as endoscopes to be disposable and safe for hygiene, but the endoscopes described in Patent Document 1 and Patent Document 2 are expensive. Disposable is difficult.

  The present invention has been made in order to solve the above-described problems, and has a sufficiently small diameter and allows observation of the inside of the body over a wide range from the front to the side, leading to improved workability of surgery, and simple An object of the present invention is to provide an endoscope that is disposable by having an optical system.

  An endoscope according to the present invention that achieves the above-described object is an endoscope that includes an optical system, and is disposed at a long body inserted into a body cavity and an end of the long body on a distal end side. The imaging unit has an imaging element in which an imaging surface is arranged along the longitudinal direction of the endoscope, and a surface on which light is incident with respect to the longitudinal direction of the endoscope. An optical lens that is arranged obliquely and forms an image of an observation range on the imaging surface, and a diaphragm provided on a light incident surface of the optical lens, and a hole portion on which light enters the imaging surface. An endoscope having a member.

  In the case of the endoscope configured as described above, since the imaging surface of the imaging device is arranged along the longitudinal direction of the endoscope, the diameter of the endoscope is reduced, and Since the optical lens is arranged so that the light incident surface is inclined with respect to the longitudinal direction, image information on the front and sides can be obtained in the direction in which the endoscope is inserted. . Therefore, the endoscope can be inserted while paying attention to the front, and the lesioned part present in the side part can be observed, leading to improvement in the workability of the operation. In addition, since an imaging device is provided inside the endoscope, an optical fiber and a relay lens for transmitting an image to the outside are unnecessary, and compared with the endoscopes described in Patent Document 1 and Patent Document 2. Cost can be reduced and a disposable endoscope can be provided.

  If the optical lens is arranged so that the center point of the hole of the aperture member is closer to the distal end side of the endoscope than the center point of the imaging surface, a wider angle range can be taken into the imaging surface. Therefore, a wider range can be observed, which leads to an improvement in the workability of the operation.

  If the optical lens is a spherical lens, the manufacturing of the optical lens is easy and inexpensive, so that the endoscope is also inexpensive and can be provided as a disposable endoscope.

  If the F-number of the spherical lens is 3.2 or more, the depth of focus becomes large, so that a clear image can be obtained without being greatly out of focus, leading to an improvement in the workability of the operation.

  If the optical lens is an aspherical lens having an axis that is rotationally symmetric, the optical lens can be manufactured easily and inexpensively. Therefore, an endoscope that is inexpensive and can be disposable is provided. be able to.

  Observation with different distances and directions from the center of the aperture of the aperture member on the imaging surface if the aperture of the aperture is offset toward the base end with respect to the rotationally symmetric axis of the optical lens Since the image of the range can be formed at three or more locations in the front, the side, and between them, a clear image can be obtained, leading to an improvement in the workability of the operation.

  The optical lens is a rotationally asymmetric lens having no rotationally symmetric axis, and the shorter the optical path length from the center of the aperture of the diaphragm member to the imaging surface, the light of the optical lens on the optical path. If the radius of curvature of the outgoing surface is small, it is possible to simultaneously obtain images in an observation range with different distances and directions from the center of the aperture of the aperture member on the imaging surface, leading to improved workability of the operation.

  If the longitudinal direction of the imaging surface is arranged along the longitudinal direction of the endoscope, an optical lens that forms an image of the observation range on the entire imaging surface can be used to achieve a clearer image with a higher number of pixels. Images can be obtained, leading to improved workability of surgery.

  If the optical lens is composed of only one lens, the endoscope can be inexpensive and a disposable endoscope can be provided.

It is a schematic structure figure of the whole system using the endoscope concerning the present invention. 1 is a cross-sectional view of an endoscope according to a first embodiment of the present invention. The optical lens of the endoscope which concerns on the 1st Embodiment of this invention, an image pick-up element, and an aperture member are shown, Furthermore, the optical path until the light from an observation range passes through an optical lens and arrives at an imaging surface was shown. FIG. It is the figure which showed an example of the image obtained using the endoscope which concerns on the 1st Embodiment of this invention. The optical lens of the endoscope which concerns on the 2nd Embodiment of this invention, an image pick-up element, and an aperture member are shown, Furthermore, the optical path until the light from an observation range passes through an optical lens and arrives at an imaging surface was shown. FIG. It is the schematic which showed the other example of arrangement | positioning of the aperture member of the endoscope which concerns on the 2nd Embodiment of this invention. The optical lens of the endoscope which concerns on the 3rd Embodiment of this invention, an image pick-up element, and a diaphragm member were shown, and also the optical path until the light from an observation range passes through an optical lens and arrives at an image pick-up surface was shown. FIG. It is sectional drawing which shows the other example of arrangement | positioning of the image pick-up element of the endoscope which concerns on embodiment of this invention. It is sectional drawing which shows the Example in the case of using the multiple optical lens of the endoscope which concerns on embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the dimension ratio of drawing is exaggerated on account of description, and may differ from an actual ratio. Further, in the following description, the proximal operation part side of the endoscope is referred to as “base end side”, and the side inserted into the body cavity is referred to as “distal end side”.

<First Embodiment>
As shown in FIG. 1, the endoscope 1 according to the first embodiment of the present invention can be used together with a control unit 8 and a display unit 9 described later to obtain an image in a body cavity.

  Hereinafter, the endoscope 1 will be described.

  As shown in FIGS. 2 and 3, an endoscope 1 according to the first embodiment of the present invention includes a long long body 11 to be inserted into a body cavity and an end portion on the distal end side of the long body 11. And an imaging unit 12 disposed in the.

  The long body 11 is a tube made of, for example, resin having flexibility, having a hollow portion 111 penetrating the inside. The outer diameter of the long body 11 is preferably 1 mm or less, but is not limited thereto.

  The imaging unit 12 includes a cylindrical case 121, a window 122 provided on the distal end side of the case 121, a light source 123 provided alongside the window 122 for illuminating the inside of the body cavity, and an internal view provided in the case 121. An imaging element 125 in which the longitudinal direction of the imaging surface 124 is arranged along the longitudinal direction of the mirror 1, and a surface 126 (hereinafter, referred to as light incident on the longitudinal direction of the endoscope 1 provided on the distal end side of the case 121). And an aperture lens 128 provided on the incident surface 126 side of the optical lens 127.

  The aperture member 128 may be a metal thin plate with a hole, but may be directly processed into a lens by printing or laser processing, and other portions than the hole only need to be shielded, so vapor deposition or etching is used. May be.

  In the imaging unit 12, the light emitted from the light source 123 passes through the transparent window 122 and illuminates the body cavity. Next, light from the observation ranges A to D illustrated in FIG. 2 is guided to the imaging surface 124 via the optical lens 127 and converted into an electrical signal by the imaging element 125. The electrical signal converted by the image sensor 125 is transmitted to the outside via the cable 129. Of the observation ranges A to D, A and B indicate the front part, and C and D indicate the side part.

  The material of the case 121 is preferably resin or metal, but is not limited thereto.

  Instead of the window portion 122, a concave lens for diffusing light from the light source may be used.

  The light source 123 is an LED that emits light by current supplied from the cable 129. The location of the light source 123 may be changed as appropriate in order to illuminate the body cavity, and a light source such as an optical fiber for irradiation disposed through the hollow portion 111 of the long body 11 may be used.

  The imaging device 125 includes an imaging surface 124 provided on a surface facing the optical lens 127 and a cable 129 for transmitting an image signal obtained by the imaging device 125 to the control unit 8.

  As described above, in the imaging element 125, the longitudinal direction of the imaging surface 124 is arranged along the longitudinal direction of the endoscope 1. This is because by optimizing the shape of the optical lens 127, among the observation areas A to D, A1 which is the front end at the front is the most proximal side of the imaging surface 124, and the side of the areas A to D is lateral. Can be imaged on the most distal side of the imaging surface 124, and the imaging surface 124 can be arranged longer along the longitudinal direction of the endoscope 1, thereby increasing the number of pixels. This is because a clear image can be obtained. Note that the image sensor 125 is not necessarily arranged in the longitudinal direction of the endoscope 1.

  The aperture member 128 has a hole 131 for allowing light to pass through in the center.

  The optical lens 127 is fixed to the case 121 so that the light incident surface 126 is inclined with respect to the longitudinal direction of the endoscope 1. The center point of the hole 131 of the diaphragm member 128 disposed in the optical lens 127 is fixed to the case 121 so that the center point of the imaging surface 124 is closer to the distal end side of the endoscope 1.

  Here, a specific design method of the optical lens 127 will be described. First, a range to be observed is set as the observation ranges A to D. In addition, A shows far away in the front, and D shows near in the side. Next, the position of the imaging element 125 and the length of the imaging surface 124 in the longitudinal direction of the endoscope 1 are set. Next, a certain point in the observation range (hereinafter referred to as an object point position) and a point on the imaging surface 124 corresponding to this point (hereinafter referred to as an image plane position) are determined. Next, a surface 130 from which the light of the optical lens 127 exits (hereinafter referred to as an exit surface) so that light from the object point position passes through the hole 131 of the aperture member 128 and forms an image at the image plane position. Set the radius of curvature. An optical lens 127 capable of forming an image in the observation ranges A to D on the entire surface of the imaging surface 124 by setting this continuously for all three-dimensional ranges of the observation ranges A to D is manufactured. Can do.

  The optical lens 127 manufactured by the above design method has the following characteristics. That is, it is a rotationally asymmetric lens that does not have a rotationally symmetric axis, and the shorter the optical path length from the center of the hole 131 of the aperture member 128 to the imaging surface 124, the shorter the outer peripheral surface 130 of the optical lens 127 on the optical path. This lens has a small radius of curvature. For example, the radius of curvature is in the range of 0.1 mm to 0.3 mm. The optical lens 127 is preferably plane-symmetric with respect to a plane (hereinafter, sometimes referred to as a longitudinal section) passing through the center of the imaging surface 124 that is cut in the sectional view shown in FIG.

  Next, the operation of the endoscope 1 according to the first embodiment of the present invention will be described.

  First, as shown in FIG. 2, the endoscope 1 is inserted into a body cavity.

  Next, the light emitted from the light source 123 passes through the transparent window 122 and illuminates the body cavity. Then, as shown in FIG. 3, the light (L1 to L4) from the observation ranges A to D passes through the hole 131 of the diaphragm member 128 and the optical lens 127 and reaches the imaging surface 124. As described above, since the optical lens 127 in which the radius of curvature of the exit surface 130 is designed so as to form an image on the imaging surface 124, all images in the observation ranges A to D are imaged on the imaging surface 124. To do. Then, the image sensor 125 converts the image signal.

  The image signal converted by the imaging element 125 is transmitted to the control unit 8 via the cable 129, and images in the observation ranges A to D are displayed on the display unit 9.

  An example of an image obtained by using the endoscope 1 according to the first embodiment of the present invention is shown in FIG. As shown in FIG. 4, among the observation ranges A to D, distortion is not observed in a range close to a line X (see FIG. 2) perpendicular to the incident surface 126 through the center of the hole 131 like B and C. An image close to a small actual image is obtained, and a distorted image is obtained as the distance from the vertical line X increases. This is because the optical lens 127 has the characteristics of a so-called fisheye lens. Although not described in the present embodiment, the control unit 8 may be provided with a function of converting the obtained image into a normal image with less distortion by computer processing and displaying the image on the display unit 9.

As described above, according to the first embodiment, since the imaging surface 124 of the imaging element 125 is arranged along the longitudinal direction of the endoscope 1, the diameter of the endoscope 1 is reduced, Since the optical lens 127 is arranged so that the light incident surface 126 is inclined with respect to the longitudinal direction of the endoscope 1, the front and the side with respect to the direction in which the endoscope 1 is inserted. Since the image information can be obtained, this improves the workability of the operation. In actual use, while observing the observation areas A and B which are the front part, the endoscope 1 is pushed forward and placed in the observation areas C and D which are the side parts to a place where the lesioned part can be observed. Observe the area closely.
Further, since the image signal from the image sensor 125 is transmitted to the control unit 8 via the cable 129, the optical fiber and the relay lens that are configured in the conventional endoscope are not necessary, and can be disposable and inexpensive. An endoscope 1 can be provided.

  The optical lens 127 is arranged so that the center point of the hole 131 of the diaphragm member 128 is closer to the distal end side of the endoscope 1 than the center point of the imaging surface 124. It is possible to form an image on the imaging surface 124 up to the range of A1 that is the frontmost end portion, and it is possible to capture a wider angle range into the imaging surface 124. For this reason, the inside of the body cavity can be observed over a wider range, leading to an improvement in the workability of the operation.

  The optical lens 127 is a rotationally asymmetric lens that does not have a rotationally symmetric axis, and the shorter the optical path length from the center of the hole 131 of the aperture member 128 to the imaging surface 124, the optical lens on the optical path. Since the curvature radius of the surface 130 from which the light 127 is emitted is small, images in the observation ranges A to D having different distances and directions from the center of the hole 131 of the aperture member 128 are simultaneously formed on the imaging surface 124. Can improve the workability of surgery.

  Further, since the longitudinal direction of the imaging surface 124 is arranged along the longitudinal direction of the endoscope 1, an optical lens 127 that forms an image in the observation range A to D on the entire imaging surface 124 is used. Thus, a clear image with a higher number of pixels can be obtained, which leads to an improvement in the workability of the operation.

  Further, since the optical lens 127 is composed of only one lens, the endoscope 1 is inexpensive and can be provided as a disposable endoscope 1.

Second Embodiment
Next, a second embodiment of the present invention will be described. Description of parts common to the first embodiment will be omitted, and only the features unique to the second embodiment will be described.

  As shown in FIG. 5, the endoscope 2 according to the second embodiment of the present invention has an axis S that is rotationally symmetric (hereinafter sometimes referred to as a rotationally symmetric axis), and the curvature of the exit surface 230. An optical lens 227 that is an aspherical lens having a radius that is not constant and has a larger curvature radius toward the outer periphery, and a hole portion 231 of the diaphragm member 228 that is arranged offset to the base end side with respect to the rotational symmetry axis S. ing. Other configurations are the same as those of the first embodiment. The offset amount is, for example, 0.05 mm, and the radius of curvature of the optical lens is in the range of, for example, 0.1 mm to 0.3 mm, but is not limited thereto.

  Next, the operation of the endoscope 2 according to the second embodiment will be described.

  As in the first embodiment, first, the endoscope 2 is inserted into the body cavity.

  Next, the light emitted from the light source 123 passes through the transparent window 122 and illuminates the body cavity. As shown in FIG. 5, the light (L5 to L7) from the observation ranges A to D passes through the hole 231 and the optical lens 227 of the diaphragm member 228 and reaches the imaging surface 124. Here, since the hole portion 231 of the diaphragm member 228 is arranged to be offset to the proximal end side with respect to the rotational symmetry axis S, the second embodiment is configured so that the imaging surface 124 has a front side, a side portion, and a space therebetween. Since it is possible to form an image at three or more locations in the longitudinal section, a clear image can be obtained from the front to the entire side, leading to improved workability of the operation.

  As described above, according to the second embodiment, since the optical lens 227 is an aspherical lens having an axis S that is rotationally symmetric, the optical lens 227 can be manufactured easily and inexpensively. The endoscope 2 is also inexpensive and can provide a disposable endoscope 2.

  Further, since the hole 231 of the diaphragm member 228 is offset from the base end side with respect to the axis S that is rotationally symmetric with respect to the optical lens 227, the center of the hole 231 of the diaphragm member 228 is removed from the imaging surface 124. Since images of observation ranges A to D having different distances and directions can be imaged at three or more locations in the front, side, and longitudinal section therebetween, a clear image can be obtained and the operability of the operation can be obtained. It leads to improvement.

  As a modification of the present embodiment, as shown in FIG. 6, the position of the hole 231 of the diaphragm member 228 does not have to be offset from the rotational symmetry axis S of the optical lens 227. In this case, it is difficult to form an image on the side portion, but there is an effect that the image is formed at at least two places in the observation ranges A to C and the optical design is facilitated.

<Third Embodiment>
Next, a third embodiment of the present invention will be described. Description of parts common to the first and second embodiments will be omitted, and only the features unique to the third embodiment will be described.

  As shown in FIG. 7, the endoscope 3 according to the third embodiment of the present invention is a spherical lens having a rotationally symmetric axis S1, a constant radius of curvature of the exit surface 330, and an F value. It has an optical lens 327 that is 3.2 or more. Other configurations are the same as those of the first embodiment. The radius of curvature of the exit surface 330 of the optical lens 327 is, for example, 0.2 mm, but is not limited to this. Here, the F value is a value obtained by dividing the focal length of the optical lens 327 by the diameter of the optical lens 327, and the larger the value, the greater the depth of focus, that is, the degree that observation is possible even when the focus is slightly deviated. Indicates that it is easy to focus on.

  Next, the operation of the endoscope 3 according to the third embodiment will be described.

  As in the first embodiment, the endoscope 3 is first inserted into the body cavity.

  Next, the light emitted from the light source 123 passes through the transparent window 122 and illuminates the body cavity. Then, as shown in FIG. 7, light (L8 to L10) from the observation ranges A to D passes through the hole 131 and the optical lens 327 of the diaphragm member 128 and reaches the imaging surface 124. Here, in the third embodiment, there is one place to form an image, but since the F value is 3.2 or more, the obtained image is not greatly out of focus, and a clear image is obtained. This will improve the workability of surgery.

  As a modification of the present embodiment, the position of the hole 131 of the throttle member 128 may be offset to the base end side as in the second embodiment. In this case, images can be formed at two positions in the longitudinal section, and a clearer image can be obtained as compared with the case where the hole 131 of the diaphragm member 128 is not offset.

  As described above, according to the third embodiment, since the optical lens 327 is a spherical lens, the optical lens 327 can be manufactured more easily and inexpensively. The endoscope 3 which can be disposable can be provided.

  In addition, since the F value of the spherical lens is 3.2 or more, a clear image can be obtained without greatly defocusing, which leads to an improvement in the workability of the operation.

(Modification example)
In the first to third embodiments according to the present invention, the image pickup device is arranged so that the image pickup surface is in the horizontal direction with respect to the longitudinal direction of the endoscope. As shown in FIG. The imaging surface 424 of the imaging device 425 may be inclined with respect to the longitudinal direction of the endoscope.

  In the first to third embodiments according to the present invention, the case where there is one optical lens is shown, but it may be composed of a plurality of lens groups 527 as shown in FIG.

  In the first to third embodiments according to the present invention, the incident surface of the optical lens is a flat surface having no curvature, but the incident surface may have a curvature.

  In the second and third embodiments according to the present invention, the form in which the image is formed in the longitudinal section is shown, but the form in which the image is formed in a section shifted laterally from the longitudinal section may be used.

  The endoscope according to the present invention is not limited to a living body, and can be applied to, for example, searching for debris during an earthquake disaster.

  Smaller F-numbers are brighter and more advantageous for observation with less light, but the focusing range is narrowed, so use a larger F-number of 3.2 or more and tilt the optical axis. By positively using “AORI” and spherical aberration, curvature of field, etc., it is possible to construct a wide angle and good resolution with a single lens.

1, 2, 3 endoscope,
11 Long body,
12 imaging unit,
124 imaging surface,
125 image sensor,
126 light incident surface;
127, 227, 327, 527 optical lenses,
128, 228 diaphragm member,
130, 230, 330 Light exiting surface,
131, 231 holes,
S, S1 Axis that are rotationally symmetric.

Claims (9)

An endoscope with a built-in optical system,
An elongated body inserted into the body cavity;
An imaging unit disposed at an end of the elongated body on the distal end side;
The imaging unit includes:
An imaging device in which an imaging surface is arranged along the longitudinal direction of the endoscope;
An optical lens in which a light incident surface is obliquely arranged with respect to a longitudinal direction of the endoscope and forms an image of an observation range on the imaging surface;
A diaphragm member provided on a light incident surface of the optical lens and having a hole portion through which light is incident on the imaging surface;
Endoscope with.   The endoscope according to claim 1, wherein the optical lens is arranged such that a center point of a hole portion of the diaphragm member is closer to a distal end side of the endoscope than a center point of the imaging surface.   The endoscope according to claim 1, wherein the optical lens is a spherical lens.   The endoscope according to claim 3, wherein an F value of the spherical lens is 3.2 or more.   The endoscope according to claim 1, wherein the optical lens is an aspherical lens having an axis that is rotationally symmetric.   The endoscope according to any one of claims 1 to 5, wherein a hole portion of the diaphragm member is arranged offset to a base end side with respect to an axis that is rotationally symmetric of the optical lens.   The optical lens is a rotationally asymmetric lens having no rotationally symmetric axis, and the shorter the optical path length from the center of the aperture of the diaphragm member to the imaging surface, the light of the optical lens on the optical path. The endoscope according to claim 1, wherein a radius of curvature of a surface from which the light exits is small.   The endoscope according to any one of claims 1 to 7, wherein a longitudinal direction of the imaging surface is arranged along a longitudinal direction of the endoscope.   The endoscope according to any one of claims 1 to 8, wherein the optical lens includes only one lens.

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