JP4373586B2 - Side-view objective optical system for capsule endoscope - Google Patents

Description

[0001]
【Technical field】
The present invention relates to a side-view type objective optical system using reflection and a side-view type objective optical system of an endoscope.
[0002]
[Prior art and its problems]
A capsule endoscope that can be used without being connected to an external device has been proposed for the purpose of reducing the pain of a subject, etc., compared to a conventional endoscope connected to an external device with a long flexible tube. The capsule endoscope uses a capsule-type in-vivo introduction part by swallowing a subject, and the inner wall of the digestive tract such as the esophagus or the small intestine is an observation target. In the body cavity, since the side surface of the capsule is in contact with the inner wall surface of the lumen, the side-view type observation optical system is more advantageous for observation, but most of the conventionally proposed capsule endoscopes are of direct view type. Therefore, a side-view type capsule endoscope has also been proposed.
[0003]
A normal side-view type endoscope can be operated from outside the body posture in the body cavity, but since a capsule endoscope is pursuing miniaturization, it usually does not have a posture control means in the body cavity. If you have posture control means, you can observe a wide range by posture operation even if the field of view of the optical system is narrow, but in capsule endoscopes that do not have posture control means, a blind spot in an optical system with a narrow viewing angle Because the part which becomes becomes wide, it is not practical.
[0004]
Even in a normal endoscope that can control the posture, if the field of view of the optical system is narrow, the endoscope must be moved finely, so a wider field of view allows more detailed and accurate inspection, and inspection time is reduced. It can be shortened.
[0005]
OBJECT OF THE INVENTION
Based on this awareness of the problem, an object of the present invention is to realize a side-view type objective optical system that can observe in a wide angle range and has few blind spots by a small optical system. Another object of the present invention is to realize a side-viewing objective optical system for an endoscope with a small-sized optical system having a wide field of view.
[0010]
Summary of the Invention
The side-view type objective optical system of the capsule endoscope according to the present invention includes: an image sensor; an objective optical system that forms an image of a portion to be examined in a body cavity on the image sensor; and an electricity that wirelessly transmits an image from the image sensor. A capsule endoscope which is housed in a sealed capsule having a smooth outer shape having a tip member and a cylindrical case , wherein the objective optical system includes an imaging optical system having a positive power ; An optical member positioned in front of the imaging optical system, and the optical member receives a light beam from an oblique front of the imaging optical system, and is formed of a spherical surface or a cylindrical surface ; A first reflecting surface composed of a concave surface that reflects the light beam forward; and a concave surface that is located on the optical axis of the imaging optical system and reflects the light beam reflected by the first reflecting surface toward the imaging optical system. A second reflecting surface; and reflected by this second reflecting surface An exit surface which emits toward the light beam to an imaging optical system; have, the tip member is bonded to the optical member, and the outer surface of the tip member, the spherical or cylindrical in optical Faculty member It is characterized by having an outer shape that is smoothly continuous with an incident surface made of a surface .
[0011]
In the side-view objective optical system of the capsule endoscope, it is desirable that the incident surface has a positive surface power.
[0012]
In the side-view objective optical system of the capsule endoscope , the incident surface, the first reflecting surface, the second reflecting surface, and the connection are arranged so that the incident surface is within the depth of field of the imaging optical system. When the shape of the image optical system is set, the subject in contact with the incident surface can be observed.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on illustrated embodiments. 1 to 4 show a cross section of a capsule endoscope according to a first embodiment to which a side-view type objective optical system of the present invention is applied. As shown in FIG. 1, the capsule endoscope is formed by adhering a tip member 30, an optical member 40, and a cylindrical case 12 in this order from the front to form a sealed capsule 10 having a smooth outer shape. The tip member 30 is bonded to the front of the optical member 40 without a gap, and is formed in an outer shape that is smoothly continuous from the optical member 40. The cylindrical case 12 is bonded to the rear of the optical member 40 without a gap, and a circuit portion (electric circuit) 20 is accommodated therein. An imaging optical system 45 having a positive power located behind the optical member 40 is fixed to the front surface of the circuit unit 20. The optical member 40 is formed of a single member made of glass or plastic. An incident surface 41 is formed obliquely in front of the optical member 40. Inside the optical member 40, a light source 21 that projects toward the incident surface 41 is fixed on the opposite side of the incident surface 41 with the optical axis of the imaging optical system 45 interposed therebetween. A lead wire 22 for supplying power from the circuit unit 20 is connected to the light source 21.
[0014]
The objective optical system of the capsule endoscope includes an optical member 40 and an imaging optical system 45. As shown in FIGS. 1, 2, and 4, the optical member 40 includes three surfaces including an incident surface 41, a first reflective surface 42, and a second reflective surface 43. The incident surface 41 is a spherical surface. The 1st reflective surface 42 and the 2nd reflective surface 43 consist of an internal reflective surface formed in the concave surface. The exit surface 46 is formed as a plane perpendicular to the optical axis of the imaging optical system 45. The imaging optical system 45 is fixed so that the optical axis is decentered with respect to the central axis of the cylindrical case 12 and is positioned at an intermediate portion between the incident surface 41 and the light source 21.
[0015]
The circuit unit 20 includes electrical components (image sensor 23, image sensor electrical component 24, transmission antenna 25, battery 26, transmission amplifier 27, power switch 28) for transmitting the observation image to the outside, and is formed in a cylindrical shape. Thus, the circuit support frame 29 in the cylindrical case 12 is fixed. The cylindrical case 12 whose rear side is closed in a hemispherical shape is provided with a through-hole 13 holding an O-ring 14 capable of watertight holding at its rear end, and a power switch 28 provided at the rear of the circuit unit 20 is provided with a sealed capsule 10 is arranged to be operable from the outside through the through hole 13. When the capsule endoscope is used, the power is turned on / off by the power switch 28.
[0016]
The capsule endoscope is introduced into a body lumen by swallowing by a subject. Since the lumen is normally collapsed, the capsule endoscope in the lumen has a posture in which the longitudinal direction coincides with the axial direction of the lumen, and the lumen wall is in close contact with the capsule surface, particularly the side surface. That is, the lumen wall that is in close contact with the surface of the optical member 40 is an observation target in the capsule endoscope, and therefore the objective optical system is configured so that the incident surface 41 is within the depth of field of the imaging optical system 45. Is set.
[0017]
Since the light source 21 directly illuminates the observation range, it is possible to obtain a bright image with no light loss due to reflection. An image in the observation range that is directly illuminated by the light source 21 is incident from an incident surface 41 provided obliquely forward of the imaging optical system 45, and is reflected forward by a concave first reflecting surface 42. Converge. The reflected light is reflected toward the imaging optical system 45 by the second inner reflecting surface which is a concave surface, further converges, exits from the exit surface 46, enters the imaging optical system 45, and is coupled onto the image sensor 23. Image. Since the image processing and signal transmission / reception performed in the circuit unit 20 are not related to the gist of the present invention, the description thereof is omitted here.
[0018]
A second embodiment is shown in FIGS. As shown in FIGS. 5 and 6, the objective optical system of the present embodiment is configured such that the incident surface 41 is configured by a cylindrical surface having a central axis orthogonal to the optical axis, and the incident surface 41 is configured by a spherical surface. The same effect as the embodiment can be obtained.
[0019]
In the above embodiments, the side-view type objective optical system according to the present invention is applied to the objective optical system of a capsule endoscope. However, the endoscope generally has an internal insertion portion and an operation portion positioned outside the body. Of course, it can also be applied to endoscopes. Furthermore, the present invention can be applied to general objective optical systems.
[0020]
【The invention's effect】
As described above, according to the side-view objective optical system of the present invention, the total length of the optical system can be shortened by the combination of the reflecting surfaces, so that the compact objective optical system capable of wide-angle observation in a small reflective space. The system is realized. In addition, when the objective optical system of the present invention is applied to an endoscope, a small-sized endoscope capable of observation over a wide angle in the peripheral direction orthogonal to the axial direction of the endoscope can be obtained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an entire capsule endoscope showing a first embodiment according to the present invention.
FIG. 2 is a cross-sectional view taken along the line II-II in FIG.
3 is a sectional view taken along line III-III in FIG.
4 is a cross-sectional view taken along line IV-IV in FIG.
FIG. 5 is a cross-sectional view of the entire capsule endoscope showing a second embodiment according to the present invention.
6 is a sectional view taken along line VI-VI in FIG.
7 is a cross-sectional view taken along line VII-VII in FIG.
8 is a cross-sectional view taken along the line VIII-VIII in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Seal capsule 12 Cylindrical case 13 Through-hole 14 O-ring 20 Circuit part (electric circuit)
21 Light source 22 Lead wire 23 Image sensor 24 Image sensor electrical component 25 Transmitting antenna 26 Battery 27 Transmitting amplifier 28 Power switch 29 Circuit support frame 30 Tip member 40 Optical member 41 Incident surface 42 First reflecting surface 43 Second reflecting surface 45 Connection Image optical system 46 exit surface

Claims (3)

An image sensor; an objective optical system that forms an image of a portion to be examined in a body cavity on the image sensor; and an electric circuit that wirelessly transmits an image from the image sensor; and a smooth outer shape having a tip member and a cylindrical case A capsule endoscope housed in a sealed capsule of shape ,
The objective optical system is
An imaging optical system having a positive power ; and an optical member positioned in front of the imaging optical system;
The optical member includes an incident surface made of a spherical surface or a cylindrical surface that takes in a light beam from an oblique front of the imaging optical system; a first reflecting surface made of a concave surface that reflects the light beam incident from the incident surface toward the front; A second reflecting surface, which is located on the optical axis of the imaging optical system and reflects the light beam reflected by the first reflecting surface toward the imaging optical system; and a light beam reflected by the second reflecting surface; emission surface that emits toward the imaging optical system and; has,
The tip member is bonded to the optical member, and has an outer shape in which the outer surface of the tip member and the incident surface formed of the spherical surface or the cylindrical surface of the optical member are smoothly continuous. A side-view type objective optical system for a capsule endoscope . In side-view type objective optical system of claim 1 capsule endoscope according incident surface is positive in the capsule has a surface power endoscope side-view type objective optical system. 3. The side-view objective optical system for a capsule endoscope according to claim 1 , wherein the incident surface, the first reflecting surface, and the first reflecting surface are arranged so that the incident surface is within the depth of field of the imaging optical system. A side-view objective optical system of a capsule endoscope in which the shape of the two reflecting surfaces and the imaging optical system is set.

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