JP4363931B2 - Capsule endoscope - Google Patents

Description

  The present invention relates to a capsule endoscope that inspects a living body or the like.

  In recent years, endoscopes have been widely adopted in the medical field and the industrial field. Recently, a capsule endoscope that does not require an insertion portion in an endoscope has been used in the medical field. The capsule endoscope does not require an insertion portion in the endoscope and has a capsule shape that is easy for a patient to swallow.

Such a conventional capsule endoscope is described in, for example, Japanese Patent Application Laid-Open No. 2003-116781. Here, an apparatus has been proposed in which two lenses having the same outer diameter as the lens frame are arranged as an objective optical system in a capsule-shaped transparent exterior member so that an image is formed on the imaging surface of the imaging unit.
However, the capsule medical device described in JP-A-2003-116781 has not been intended to perform a wide range of observation.

On the other hand, another conventional capsule endoscope is described in, for example, PCT WO02 / 054932 A2. Here, an apparatus in which a plurality of objective optical systems are arranged so that the observation directions are different from each other has been proposed. As a result, an observation range wider than that of a single optical path can be obtained.
However, since the capsule endoscope described in PCT WO02 / 054932 A2 has a plurality of objective optical systems, the capsule outer diameter tends to be large and the structure is complicated.

Thus, it cannot be said that the conventional capsule endoscope has a sufficiently large angle of view of the objective optical system with respect to the imaging unit, and is, for example, about 90 to 120 °. Therefore, it cannot be said that it is sufficient to achieve both miniaturization and improvement of observation ability around the capsule.
JP 2003-116781 A PCT WO02 / 054932 A2 publication

  The problem to be solved is that it has been difficult to achieve both a reduction in size and a wide observation range in a capsule endoscope.

The capsule endoscope according to the present invention includes an illuminating unit for irradiating a subject with predetermined illumination light, an imaging unit for imaging a portion illuminated by the illuminating unit, and a front part of the imaging unit. A capsule endoscope having a provided objective optical system and a transparent cover covering at least the front of the objective optical system,
The objective optical system is
In the objective optical system, the first lens is disposed on the foremost side and formed in a concave meniscus shape that is convex on the object side, and is disposed behind the first lens and formed in a plano-concave shape. A lens system composed of three single lenses: a second lens; and a third lens disposed behind the second lens and in front of the imaging means and formed in a convex shape ; An aperture stop disposed in front of the third lens,
The second lens is disposed at a position at which a subject image from the first lens can pass through the brightness stop, and the second lens, the second lens, and the third lens. When the outer diameters are D1, D2, and D3,
D1> D2 ≧ D3
It has the relationship of these.

  The capsule endoscope of the present invention can take a large angle of view of the objective optical system while maintaining a small size, and can perform observation over a wide range of, for example, 140 ° or more.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 to 5 relate to a first embodiment of the present invention, and FIG. 1 is an overall configuration diagram showing a capsule endoscope apparatus of the first embodiment. FIG. 1 (A) is an explanatory view showing a state when a capsule endoscope is swallowed and an endoscopic examination is performed, and FIG. 1 (B) is when the extracorporeal unit of FIG. 1 (A) is removed and connected to a personal computer. It is explanatory drawing which shows the mode. FIG. 2 is a cross-sectional view showing the internal configuration of the capsule endoscope of FIG. FIG. 3 is an enlarged view showing the distal end side of the capsule endoscope of FIG. 4 is a cross-sectional view taken along the line AA in FIG. FIG. 5 is a sectional view showing a modification of FIG.

    As shown in FIG. 1A, a capsule endoscope apparatus 1 according to the first embodiment of the present invention includes a capsule endoscope 3, an antenna unit 4, and an extracorporeal unit 5. The capsule endoscope 3 passes through the body cavity duct by being swallowed from the mouth of the patient 2. At that time, the inner wall surface of the body cavity is optically imaged, and the captured image signal is transmitted wirelessly outside the body. The antenna unit 4 is provided outside the body of the patient 2 and receives a signal transmitted from the capsule endoscope 3. The extracorporeal unit 5 has a function of storing images (arranged outside the patient 2).

The extracorporeal unit 5 has a built-in compact flash (R) hard disk having a capacity of, for example, 1 GB in order to store image data. The extracorporeal unit 5 can be connected to the display system 6 in FIG. 1B during or after the examination. Therefore, the image data stored in the extracorporeal unit 5 can be displayed on the display system 6.
That is, as shown in FIG. 1B, the extracorporeal unit 5 is detachably connected to a personal computer (hereinafter abbreviated as a personal computer) 7 constituting the display system 6 by a communication cable such as a USB cable 8. The

  The personal computer 7 takes in the image data stored in the extracorporeal unit 5 and performs processing such as storing it in the internal hard disk and displaying it. The display unit 9 can display the stored image or the processed image. For example, a keyboard 10 is connected to the personal computer 7 as an operation panel for performing data input operations and the like.

  The USB cable 8 may be any communication standard of USB1.0, USB1.1, and USB2. In addition, serial data communication complying with RS-232C and IEEE 1394 standards may be performed, and the present invention is not limited to performing serial data communication, and parallel data communication may be performed.

  As shown in FIG. 1A, when swallowing the capsule endoscope 3 and performing an endoscopic examination, the patient 2 wears a shield shirt 11 having a shield function. Inside the shield shirt 11, an antenna unit 4 to which a plurality of antennas 12 are attached is mounted. The antenna unit 4 is picked up by the capsule endoscope 3 and receives a signal transmitted from an antenna incorporated therein. The received signal is sent to the extracorporeal unit 5 connected to the antenna unit 4 so as to store the captured image. The extracorporeal unit 5 is attached to the belt of the patient 2 by a detachable hook, for example.

  The extracorporeal unit 5 has, for example, a box shape, and is provided with, for example, a liquid crystal monitor 13 as a display device for displaying an image and an operation button 14 for performing a control operation on the front surface. The extracorporeal unit 5 includes a transmission / reception circuit (communication circuit), a control circuit, an image data display circuit, and a power source.

  As shown in FIG. 2, the capsule endoscope 3 according to the first embodiment includes an outer case 16 and a transparent cover 17. The outer case 16 is cylindrical and has a structure in which the rear end is rounded and closed. A hemispherical transparent cover 17 is connected and fixed in a watertight manner to the open end portion of the outer case 16 that is open. In this way, the inside of the capsule endoscope 3 is sealed, and the following built-in items are stored in the sealed capsule container. The outer case 16 is made of a synthetic resin such as polysulfone or polyurethane. The transparent cover 17 is made of a transparent synthetic resin such as polycarbonate, cycloolefin polymer, PMMA (polymethyl methacrylate), or polyurethane.

  In the central portion facing the transparent cover 17, an objective optical system 23 is disposed between the front end side lens frame 20 and the rear end side lens frame 22 provided on the front surface side of the imaging substrate 21, and the image forming position thereof is at the imaging position. For example, a CMOS (Complementary Metal-Oxide Semiconductor) imager 24 is arranged as an imaging means. The CMOS imager 24 is attached to the front surface of the imaging substrate 21.

  In this embodiment, the imaging surface of the CMOS imager 24 is protected by a cover glass 25, and a rear end side lens frame 22 is attached so as to cover the cover glass 25. Further, the cylindrical portion of the rear end side lens frame 22 is adapted to be fitted to the front end side lens frame 20. Therefore, the front end side lens frame 20 is moved back and forth in the direction of the optical axis O to perform focus adjustment and then fixed with an adhesive.

  Note that there is a possibility that dust such as shavings of the rear end side lens frame 22 may be generated during focus adjustment. However, the cover glass 25 can prevent these dusts from adhering to the front surface of the imaging surface of the CMOS imager 24. Therefore, a good image is always obtained.

  An illumination substrate 26 is disposed on the outer periphery of the front end side lens frame 20. And white LED etc. as a light emission part are provided in several places of this illumination board | substrate 26. FIG. The white LED constitutes an illumination unit 37 that is an illumination unit. As will be described later, the illumination unit 37 is attached symmetrically with respect to the objective optical system 23. In the figure, O ′ indicates the central axis (the direction of the emission angle of 0 °) of the illumination light emitted by each white LED of the illumination unit 37.

A power supply unit 27 that supplies operating power to each unit is provided on the rear side of the imaging substrate 21, and a wireless communication unit 28 that performs wireless transmission with the outside of the capsule is provided on the rear side of the power supply unit 27. It has been.
The power supply unit 27 is arranged so that two button-type batteries 30 as built-in power supplies for supplying operating power are stacked in the axial direction of the capsule container. Via the power supply board 32.

  The power supply substrate 32 is provided with an internal switch 33 formed by, for example, a bias magnet 33a and a reed switch 33b, and the operating power supplied from the battery 30 is turned on and off. The power supply substrate 32 is connected to the imaging substrate 21 and the wireless substrate 35 constituting the wireless communication unit 28 via the connecting flexible substrate 34. Further, the imaging substrate 21 is connected to the illumination substrate 26 via a connecting flexible substrate 34.

  The wireless communication unit 28 includes a wireless substrate 35 and a wireless antenna 36. A wireless antenna 36 is provided on the wireless substrate 35. Further, the wireless board 35 is provided with a wireless communication circuit (not shown). The wireless communication circuit selectively extracts a carrier wave of the radio wave received from the extracorporeal unit 5 received by the wireless antenna 36, demodulates and outputs a control signal to each component circuit, etc. For example, an information (data) signal such as a video signal from a circuit or the like is modulated with a carrier wave having a predetermined frequency and transmitted from the wireless antenna 36 as a radio wave.

In addition, an electronic component 21 a such as a resistor, a capacitor, or a diode is mounted on the back side of the imaging substrate 21, and the CMOS imager 24 is driven in response to a signal from the extracorporeal unit 5. Further, the image pickup substrate 21 is provided with a drive processing circuit (not shown), and performs signal processing and control processing on the image pickup signal output from the CMOS imager 24.
Further, on the illumination board 26, a chip component 26a constituting an LED drive circuit (not shown) is mounted on the back side. By this LED drive circuit, the white LED of the illumination unit 37 can be flashed intermittently.

  When the internal switch 33 of the power supply board 32 is turned on, the operating power from the battery 30 is supplied from the power supply board 32 to the imaging board 21 and the wireless board 35 via the connecting flexible board 34, and further to the illumination board 26. Supplied. The wireless communication unit 28 receives the radio wave from the extracorporeal unit 5 by the wireless antenna 36, and the wireless communication circuit demodulates and outputs a control signal to the drive processing circuit of the imaging board 21 and the LED drive circuit of the illumination board 26. To work.

  The LED drive circuit causes the white LED of the illumination unit 37 to intermittently flash. In synchronization with this, the drive processing circuit drives the CMOS imager 24. The CMOS imager 24 takes an observation image illuminated by the illumination light from the LED and captured by the objective optical system 23.

  The drive processing circuit processes the imaging signal from the CMOS imager 24 to obtain a video signal. Then, the obtained video signal is output to the wireless communication circuit of the wireless communication unit 28. The wireless communication circuit of the wireless communication unit 28 modulates the video signal and transmits it as a radio wave from the wireless antenna 36.

Here, in the conventional capsule endoscope, the angle of view of the objective optical system with respect to the imaging unit is about 90 to 120 °, and it cannot be said that the observation capability around the capsule is sufficient.
Therefore, in this embodiment, a wide range of observation can be performed by means of devising the lens shape of the objective optical system 23. More specifically, an angle of view of 140 ° or more was obtained.

First, a detailed configuration of the distal end side of the capsule endoscope 3 will be described with reference to FIG.
As shown in FIG. 3, in the capsule endoscope 3, the rear end side lens frame 22 is fitted to the rear end side of the front end side lens frame 20. The objective optical system 23 includes a first lens 41, a second lens 42, and a third lens. Here, the first lens 41 is the most advanced lens.

In the distal end side lens frame 20, the most advanced lens 41 is held and fixed at the distal end side large diameter portion 20 a, and the second lens 42 is held and fixed behind the most advanced lens 41.
On the other hand, the third lens 43 is held and fixed at the front end side of the rear end side lens frame 22, and the front side of the imaging substrate 21 is bonded and fixed to the rear end side by a light shielding adhesive 44. In addition, before and after the third lens 43, an aperture stop 45 is disposed on the front side, and a flare stop 46 is disposed on the back side.

  The rear end side lens frame 22 integrated with the imaging substrate 21 is fitted to the rear end side of the front end side lens frame 20. Therefore, the front-end side lens frame 20 and the rear-end side lens frame 22 are moved relative to each other to perform focus adjustment, and thereafter, the adhesive 47 is bonded and fixed. In this way, the imaging unit 48 is configured together with the objective optical system 23. Further, on the outer peripheral side of the front end side lens frame 20, the front side of the illumination board 26 is abutted against the lens frame abutment surface 20b.

  A transparent cover 17 is fitted to the opening end portion on the front end side of the outer case 16 and is fixed in a watertight manner with a watertight adhesive. A fitting portion between the outer case 16 and the transparent cover 17 is provided with a retaining portion 49 that is formed in an uneven shape, and a watertight adhesive is applied to the gap. The transparent cover 17 is arranged with the front side of the illumination board 26 butted against the cover-side butting surface 17a.

Here, in the present embodiment, the state-of-the-art lens 41 is formed in a shape that is larger than the outer diameter of the rear lens and is convex toward the object side. More specifically, the outer diameter D1 of the most advanced lens 41 is such that D1> D2 ≧ D3 with respect to the outer diameter D2 of the second lens 42 and the outer diameter D3 of the third lens 43. Is formed. The most advanced lens 41 is formed in a meniscus shape that is convex toward the object side, and has negative refractive power.

  Thereby, the state-of-the-art lens 41 can capture light from a wider range than before, and can capture the captured light on the imaging surface of the CMOS imager 24 via the second lens 42 and the third lens 43. It is like that. More specifically, an angle of view of 140 ° or more can be obtained.

The second lens 42 is formed in a plano-concave shape, and is arranged so that the subject image from the most advanced lens 41 can pass through the aperture stop 45.
Furthermore, in the present embodiment, the front end surface 37a of the illuminating section 37 is arranged so as to be substantially coincident with or behind the lens frame front end surface 41a of the most advanced lens 41. More specifically, the front end surface 37a of the illuminating unit 37 is a distance H2 from the front end surface 17b of the transparent cover 17 to the front end surface 37a of the illuminating unit 37, and the front end surface 17b of the transparent cover 17 The distance H1 to the lens frame front end surface 41a is arranged so as to satisfy the relationship of H2 ≧ H1.

  Further, as shown in FIG. 4, the illumination unit 37 includes a plurality of white LEDs 51 with respect to the center of the longitudinal axis so as to surround the tip lens frame 20. In FIG. 4, four white LEDs 51 are arranged. Reference numeral 52 denotes a connection electrode portion provided on the illumination board 26, and is electrically connected to the illumination unit 37.

Moreover, you may form an illumination part in ring shape, as shown in the modification of FIG.
As shown in FIG. 5, the ring-shaped illumination part 37A has a plurality of white LEDs 51 arranged concentrically. In FIG. 5, twelve white LEDs 51 are arranged. In this case, since the ring-shaped illumination part 37A can provide many white LEDs 51 in a narrow space, the light distribution is good and the illumination range can be easily brightened.

With the illumination light from the plurality of white LEDs 51 arranged in the illumination units 37 and 37A, the capsule endoscope 3 obtains a composite illumination range in which the single illumination ranges are combined, and observation is performed by the composite illumination range. The range is captured by a state-of-the-art lens 41 at a wide angle of 140 ° or more and can be captured by the CMOS imager 24.
As a result, the capsule endoscope 3 of the present embodiment can take a wide angle of view of the objective optical system 23 at a wide angle of 140 ° or more, and can observe a wide range around the capsule. Get the effect.

6 and 7 relate to a second embodiment of the present invention, FIG. 6 is an enlarged view showing the distal end side of the capsule endoscope of the second embodiment, and FIG. 7 is a transparent view of the capsule endoscope of FIG. It is a B arrow view at the time of removing a cover.
In the first embodiment, the state-of-the-art lens 41 of the objective optical system 23 is arranged so as to be separated from the transparent cover 17. However, in the second embodiment, the objective optical system is arranged with respect to the transparent cover 17. 23 cutting-edge lenses 41 are in close contact with each other. Since the other configuration is the same as that of the first embodiment, the description thereof will be omitted, and the same components will be described with the same reference numerals.

That is, as shown in FIG. 6, the capsule endoscope 3 </ b> B of the second embodiment is configured such that the most advanced lens 41 of the objective optical system 23 is partly in close contact with the transparent cover 17.
Here, in the second example, as in the first example, the most advanced lens 41 of the objective optical system 23 is larger than the lens outer diameters of the second lens 42 and the third lens 43 that are located behind it. The outer diameter is formed so as to be convex toward the object side.

  When the angle is wide, the depth of field increases, and the subject is focused from near to far. For this reason, in the capsule endoscope 3B of the second embodiment, the state-of-the-art lens 41 of the objective optical system 23 is brought close to and in close contact with the transparent cover 17.

  As a result, the capsule endoscope 3B of the second embodiment has the state-of-the-art lens 41 of the objective optical system 23 in intimate contact with the transparent cover 17, so that the entire length can be shortened and the size can be reduced. is there. Further, since the capsule endoscope 3B of the second embodiment forms the lens frame 60 in which the front end side lens frame and the rear end side lens frame are integrated, further miniaturization is possible.

Further, the capsule endoscope 3B of the second embodiment is different in the configuration of the illumination unit 37B.
As shown in FIG. 7, the illumination unit 37B is configured such that an inclined base 61 is provided on the front side of the illumination board 26B formed in a donut shape so that the white LED 51 faces a predetermined angle. The illumination unit 37B is connected to the LED drive circuit by the connection terminal 62.

Thereby, the illumination unit 37B faces the direction in which the illumination center direction of the white LED 51 substantially coincides with the observation center direction of the imaging unit 48B, and various directions of the forward direction, the outward direction, and the inward direction that are the peripheral direction or the central direction. be able to.
Therefore, the capsule endoscope 3B according to the second embodiment can further expand or set the composite illumination range obtained by combining the single illumination ranges by the illumination unit 37B to a desired illumination range.

8 and 9 relate to the third embodiment of the present invention, FIG. 8 is an enlarged view showing the distal end side of the capsule endoscope of the third embodiment, and FIG. 9 is an inside of the capsule mold showing a modification of FIG. It is an enlarged view which shows the front end side of an endoscope.
In the first and second embodiments, the center of curvature of the transparent cover 17 is formed to be constant. In the third embodiment, the shape of the transparent cover is changed to change the center of curvature of the transparent cover. Configure. Since the other configuration is the same as that of the first embodiment, the description thereof will be omitted, and the same components will be described with the same reference numerals.

As shown in FIG. 8, the capsule endoscope 3C of the third embodiment is configured such that the entrance pupil position 70 near the center of the imaging unit 48 and the center of curvature of the transparent cover 17C substantially coincide.
More specifically, the transparent cover 17 </ b> C is a substantially hemispherical shape that protrudes in a substantially hemispherical shape so as to cover the most advanced lens 41 of the objective optical system 23 constituting the imaging unit 48 in the vicinity of the most central portion on the most advanced side. A hemispherical portion 71 is formed. For example, the near point side of the depth of field of the objective optical system 23 is set to the distance of the curvature radius Ro from the outer surface of the substantially hemispherical portion 71, that is, the position of the entrance pupil position 70. In FIG. 8, R1 is the radius of curvature of the inner surface of the substantially hemispherical portion 71, and R2 is the radius of curvature of the outer surface of the most advanced lens 41.

As a result, in the capsule endoscope 3C of the third embodiment, the entrance pupil position 70 near the center of the imaging unit 48 and the center of curvature of the substantially hemispherical portion 71 of the transparent cover 17C substantially coincide with each other. Thus, it is possible to obtain an observation range of 180 ° or more, particularly up to about 210 °, compared to the second embodiment.
Further, in the capsule endoscope 3C of the third embodiment, the illumination unit 37C is disposed on the side with respect to the substantially hemispherical part 71 of the transparent cover 17C. Therefore, the capsule endoscope 3C of the third embodiment prevents the illumination light from the white LED 51 of the illumination unit 37C from being incident on the objective optical system 23 when it is reflected by the inner surface of the transparent cover 17C. This makes it less susceptible to unwanted light such as flares.

  Therefore, the capsule endoscope 3C according to the third embodiment can obtain an observation range from about 180 ° to 210 °, and can obtain a good subject image without being affected by unnecessary light such as flare caused by illumination light. To get the effect.

Note that the capsule endoscope may be configured to change the center of curvature of the transparent cover by changing the shape of the transparent cover as shown in FIG.
As shown in FIG. 9, the capsule endoscope 3D according to the modified example is formed in a substantially elliptical convex shape having two curvature centers on the transparent cover 17D, and further illuminated so as to substantially coincide with these two curvature centers. The part 37D is arranged. In FIG. 9, R3 is the radius of curvature of the inner surface of the transparent cover 17D.

  Reference numeral 81 denotes a connection cylinder provided between the imaging board 21 and the illumination board 26 </ b> D. The illumination board 26 </ b> D is fixed to the imaging board 21 via the connection cylinder 81. Reference numeral 42b denotes a fourth lens of the objective optical system 23D.

  Thereby, in the capsule endoscope 3D of the modification, the reflected light reflected on the inner peripheral surface side of the transparent cover 17D returns to the illuminating unit 37D side, so that the flare caused by the illumination light is further increased than the third embodiment. Therefore, it is difficult to be affected by unnecessary light, and a good subject image can be obtained.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the invention.
The embodiment of the present invention has been described by taking the CMOS as an example of the image pickup means. However, the image pickup means is not limited to the CMOS, and a solid-state image pickup device such as a CCD (charge coupled device) or other image pickup means may be used. . Further, for example, the present invention may be applied to a device that performs observation in a plurality of directions such as front and rear, front and side. Moreover, you may apply to what inserts transanally other than swallowing type, and the thing inserted transendoscopically.

[Appendix]
(Additional item 1)
The capsule endoscope includes an illuminating unit, an imaging unit that images a portion illuminated by the illuminating unit, an objective optical system in front of the imaging unit, and a transparent cover that covers at least the front of the objective optical system. And
A capsule endoscope characterized in that the most advanced lens of the objective optical system has an outer diameter larger than the outer diameter of the rear lens, and is formed in a convex shape toward the object side.

(Appendix 2)
The capsule endoscope includes an illuminating unit, an imaging unit that images a portion illuminated by the illuminating unit, an objective optical system in front of the imaging unit, and a transparent cover that covers at least the front of the objective optical system. And
A capsule endoscope, wherein the most advanced lens of the objective optical system has a meniscus shape that is convex toward the object side, and has a negative refractive power.

(Additional Item 3)
2. The capsule endoscope according to appendix 1, wherein the most advanced lens of the objective optical system has a meniscus shape that is convex toward the object side and has negative refractive power.
(Appendix 4)
Additional notes characterized in that the front end surface of the illumination means is substantially coincident with or behind the front end surface of the lens frame holding the most advanced lens of the objective optical system. The capsule endoscope according to 1 or 2.

(Appendix 5)
The transparent cover has a substantially hemispherical portion covering at least the front of the objective optical system, and is arranged so that the center of curvature of the substantially hemispherical portion substantially coincides with the pupil position near the center of the imaging means. Item 3. The capsule endoscope according to Additional Item 1 or 2, wherein
(Appendix 6)
The capsule endoscope according to claim 1 or 2, wherein the transparent cover has two centers of curvature, and the illuminating means is disposed so as to substantially coincide with the two centers of curvature. .

(Appendix 7)
The capsule endoscope according to appendix 1 or 2, wherein the second lens facing the most advanced lens of the objective optical system has a plano-concave shape.
(Appendix 8)
3. The capsule endoscope according to claim 1 or 2, wherein at least a part of an outer surface of the most advanced lens of the objective optical system is disposed in close contact with the inner surface of the transparent cover.

(Appendix 9)
3. The capsule endoscope according to appendix 1 or 2, wherein the illuminating unit includes a plurality of light emitting units arranged to surround the imaging unit.
(Appendix 10)
6. The capsule endoscope according to appendix 5, wherein the center of curvature of the most advanced lens is formed so as to substantially coincide with the pupil position of the imaging means.

(Appendix 11)
The illumination unit has a plurality of light emitting units arranged so as to surround the periphery of the imaging unit, and the plurality of light emitting units have at least a part of the illumination center direction with respect to the observation center direction of the imaging unit. The capsule endoscope according to Additional Item 1 or 2, wherein the capsule endoscope is disposed in either the circumferential direction or the central direction.

(Appendix 12)
The capsule endoscope includes an illuminating unit, an imaging unit that images a portion illuminated by the illuminating unit, an objective optical system in front of the imaging unit, and a transparent cover that covers at least the front of the objective optical system. And
The outermost lens of the objective optical system has an outer diameter larger than the outer lens diameter behind it,
The transparent cover has a substantially hemispherical portion that covers at least the front of the objective optical system, and is arranged so that the center of curvature of the substantially hemispherical portion substantially coincides with the pupil position near the center of the imaging means. a capsule endoscope characterized by and.

(Additional Item 13)
The capsule endoscope includes an illuminating unit, an imaging unit that images a portion illuminated by the illuminating unit, an objective optical system in front of the imaging unit, and a transparent cover that covers at least the front of the objective optical system. And
The outermost lens of the objective optical system has an outer diameter larger than the outer lens diameter behind it,
The capsule endoscope is characterized in that the transparent cover has two centers of curvature, and the illumination means is arranged so as to substantially coincide with the two centers of curvature.

(Appendix 14)
A capsule endoscope having an illuminating unit, an imaging unit that images a portion illuminated by the illuminating unit, an objective optical system in front of the imaging unit, and a transparent cover that covers at least the front of the objective optical system. And
The outermost lens of the objective optical system has an outer diameter larger than the rear lens outer diameter, and is formed in a shape that is convex toward the object side,
The transparent endoscope has two curvature centers, and the illuminating means is arranged so as to substantially coincide with the two curvature centers.

(Appendix 15)
The capsule mold according to any one of appendices 12 to 14, wherein the most advanced lens of the objective optical system has a meniscus shape that is convex toward the object side and has a negative refractive power. Endoscope.
(Appendix 16)
Additional notes characterized in that the front end surface of the illumination means is substantially coincident with or behind the front end surface of the lens frame holding the most advanced lens of the objective optical system. The capsule endoscope according to any one of 12 to 14.

(Appendix 17)
15. The capsule endoscope according to any one of appendices 12 to 14, wherein the second lens facing the most advanced lens of the objective optical system has a plano-concave shape.
(Appendix 18)
The capsule-type internal view according to any one of appendices 12 to 14, wherein at least a part of an outer surface of the most advanced lens of the objective optical system is disposed in close contact with the inner surface of the transparent cover mirror.

(Appendix 19)
15. The capsule endoscope according to any one of additional items 12 to 14, wherein the illuminating unit includes a plurality of light emitting units arranged so as to surround the periphery of the imaging unit.
(Appendix 20)
The capsule endoscope according to appendix 19, wherein the plurality of light emitting units are arranged such that at least a part of the illumination center direction substantially coincides with the observation center direction of the imaging unit.
(Appendix 21)
The additional light item 19 is characterized in that the plurality of light emitting units are arranged such that at least a part of the illumination center direction thereof is directed to either the peripheral direction or the central direction with respect to the observation center direction of the imaging unit. The capsule endoscope as described.

1 is an overall configuration diagram illustrating a capsule endoscope apparatus according to a first embodiment. It is sectional drawing which shows the internal structure of the capsule type | mold endoscope of FIG. FIG. 3 is an enlarged view showing a distal end side of the capsule endoscope of FIG. 2. It is AA sectional drawing of FIG. It is sectional drawing which shows the modification of FIG. It is an enlarged view which shows the front end side of the capsule endoscope of 2nd Example. FIG. 7 is a B arrow view when the transparent cover of the capsule endoscope of FIG. 6 is removed. It is an enlarged view which shows the front end side of the capsule endoscope of 3rd Example. It is an enlarged view which shows the front end side of the capsule type endoscope which shows the modification of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Capsule type | mold endoscope apparatus 3 Capsule type | mold endoscope 16 Exterior cover 17 Transparent cover 20 Front end side lens frame 21 Imaging substrate 22 Rear end side lens frame 23 Objective optical system 24 CMOS imager (imaging means)
26 Illumination board 37 Illumination part (illumination means)
41 State-of-the-art lens 42 Second lens 43 Third lens 48 Imaging unit

Attorney Susumu Ito

Claims (2)

An illuminating means for irradiating a subject with predetermined illumination light; an imaging means for imaging a portion illuminated by the illuminating means; an objective optical system disposed in front of the imaging means; and at least the A capsule endoscope having a transparent cover covering the front of the objective optical system,
The objective optical system is
In the objective optical system, a first lens is disposed on the foremost side and formed in a concave meniscus shape that is convex on the object side, and is disposed behind the first lens and formed in a plano-concave shape. A lens system composed of three single lenses: a second lens; and a third lens disposed behind the second lens and in front of the imaging means and formed in a convex shape ;
An aperture stop disposed in front of the third lens;
With
The second lens is disposed at a position where a subject image from the first lens can pass through the aperture stop,
When the outer diameters of the first lens, the second lens, and the third lens are D1, D2, and D3, respectively,
D1> D2 ≧ D3
A capsule endoscope characterized by having the following relationship. The illuminating means has a plurality of light emitting units arranged to surround the imaging means,
The plurality of light emitting units include at least one first light emitting unit disposed so that an illumination center direction is substantially aligned with an observation center direction of the imaging unit, and the illumination center direction is the imaging unit. 2. The capsule endoscope according to claim 1, further comprising at least one second light emitting unit disposed to face a direction different from the observation center direction.

Images