WO2010110349A1 - カプセル型内視鏡用撮像光学系 - Google Patents
カプセル型内視鏡用撮像光学系 Download PDFInfo
- Publication number
- WO2010110349A1 WO2010110349A1 PCT/JP2010/055140 JP2010055140W WO2010110349A1 WO 2010110349 A1 WO2010110349 A1 WO 2010110349A1 JP 2010055140 W JP2010055140 W JP 2010055140W WO 2010110349 A1 WO2010110349 A1 WO 2010110349A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- optical system
- image
- imaging optical
- lens
- imaging
- Prior art date
Links
Images
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B13/00—Optical objectives specially designed for the purposes specified below
- G02B13/04—Reversed telephoto objectives
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B1/00—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor
- A61B1/06—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor with illuminating arrangements
- A61B1/0625—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor with illuminating arrangements for multiple fixed illumination angles
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B3/00—Simple or compound lenses
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B1/00—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B1/00—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor
- A61B1/00064—Constructional details of the endoscope body
- A61B1/00071—Insertion part of the endoscope body
- A61B1/0008—Insertion part of the endoscope body characterised by distal tip features
- A61B1/00096—Optical elements
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B1/00—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor
- A61B1/00163—Optical arrangements
- A61B1/00188—Optical arrangements with focusing or zooming features
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B1/00—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor
- A61B1/04—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor combined with photographic or television appliances
- A61B1/041—Capsule endoscopes for imaging
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B1/00—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor
- A61B1/06—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor with illuminating arrangements
- A61B1/0607—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor with illuminating arrangements for annular illumination
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B13/00—Optical objectives specially designed for the purposes specified below
- G02B13/06—Panoramic objectives; So-called "sky lenses" including panoramic objectives having reflecting surfaces
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B13/00—Optical objectives specially designed for the purposes specified below
- G02B13/18—Optical objectives specially designed for the purposes specified below with lenses having one or more non-spherical faces, e.g. for reducing geometrical aberration
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B23/00—Telescopes, e.g. binoculars; Periscopes; Instruments for viewing the inside of hollow bodies; Viewfinders; Optical aiming or sighting devices
- G02B23/24—Instruments or systems for viewing the inside of hollow bodies, e.g. fibrescopes
- G02B23/2407—Optical details
- G02B23/2423—Optical details of the distal end
- G02B23/243—Objectives for endoscopes
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B23/00—Telescopes, e.g. binoculars; Periscopes; Instruments for viewing the inside of hollow bodies; Viewfinders; Optical aiming or sighting devices
- G02B23/24—Instruments or systems for viewing the inside of hollow bodies, e.g. fibrescopes
- G02B23/26—Instruments or systems for viewing the inside of hollow bodies, e.g. fibrescopes using light guides
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B1/00—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor
- A61B1/04—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor combined with photographic or television appliances
- A61B1/05—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor combined with photographic or television appliances characterised by the image sensor, e.g. camera, being in the distal end portion
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B1/00—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor
- A61B1/06—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor with illuminating arrangements
- A61B1/0661—Endoscope light sources
- A61B1/0676—Endoscope light sources at distal tip of an endoscope
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B1/00—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor
- A61B1/06—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor with illuminating arrangements
- A61B1/0661—Endoscope light sources
- A61B1/0684—Endoscope light sources using light emitting diodes [LED]
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M39/00—Tubes, tube connectors, tube couplings, valves, access sites or the like, specially adapted for medical use
- A61M39/02—Access sites
- A61M39/0247—Semi-permanent or permanent transcutaneous or percutaneous access sites to the inside of the body
- A61M2039/0279—Semi-permanent or permanent transcutaneous or percutaneous access sites to the inside of the body for introducing medical instruments into the body, e.g. endoscope, surgical tools
Definitions
- the present invention relates to an imaging optical system of a capsule endoscope that is swallowed into the body and used.
- Capsule endoscopes are of a size that can be swallowed by the subject, so that the burden on the patient when swallowing the insertion part and insertion of the insertion part into the body for a long time like an insertion endoscope This has the advantage that the burden on the patient is eliminated.
- the capsule endoscope is shaped like a dome so that it can easily move along a tubular path after being swallowed into the body, and a cylindrical capsule body is connected to this transparent cover.
- the optical axis of the imaging optical system is usually designed to pass through the center of the transparent cover. Therefore, the imaging optical system has not only a light beam close to the optical axis but also a light beam with a large incident angle through the periphery of the transparent cover. Is also incident. Since the object (subject) distance increases on the optical axis, and the object distance tends to be closer as the imaging angle of view increases, a planar subject is imaged on a planar imaging surface perpendicular to the optical axis. In a normal imaging optical system, the range in which good imaging can be obtained is very limited.
- an imaging optical system with a wide angle of view is known as known from Patent Document 1, but if the optical design is performed so that the peripheral portion of the subject is in focus, the central portion is outside the range of the depth of field. If the focus is focused on the central portion, the peripheral portion will be out of the depth of field and the peripheral portion will be blurred.
- the imaging optical systems disclosed in Patent Documents 2 and 3 align the image plane in the vicinity of the imaging surface at the center of the screen and the maximum angle of view, so that the entire subject including not only the central portion of the subject but also the peripheral portion is included. Is devised to fit within the depth of field.
- JP 2006-61438 A Japanese Patent No. 4128504 Japanese Patent No. 4128505
- the optical system described in the above-mentioned prior art employs a front diaphragm, it is advantageous in reducing the outer diameter of the lens on the object side, but vignetting occurs due to the thickness of the diaphragm, or immediately after the diaphragm. Since the radius of curvature of the lens surface is large, there is a drawback in that the loss of light amount when the angle is further increased.
- the optical system may generate a negative curvature of field.
- the Petzval sum can be increased by a positive value using the third-order aberration coefficient.
- a low refractive index material is generally used for the positive lens constituting the optical system, and a high refractive index material is used for the negative lens.
- the present invention has been made in view of the above background, and is directed toward an imaging optical system by widening the angle of view and aligning the image plane in the vicinity of the imaging plane perpendicular to the optical axis over the entire angle of view.
- An object of the present invention is to provide an imaging optical system for a capsule endoscope in which an entire object surface curved in a concave shape can be accommodated within a depth of field.
- the imaging optical system of the present invention has a concave object surface to be imaged, and when imaging with the object surface facing the object surface, ⁇ 5.0 ⁇ ⁇ Zr / ⁇ Zp ⁇ 5. It is configured to satisfy the condition of 0. Where ⁇ Zr represents the difference between the real image plane position with respect to the luminous flux with the maximum field angle 2 ⁇ max and the real image plane position with respect to the luminous flux with the half angle of view ⁇ max, and Zp represents the intersection between the object plane and the principal ray with 2 ⁇ max.
- This condition is preferably suitable for an optical system having a maximum field angle 2 ⁇ max of 135 ° or more.
- the maximum angle of view 2 ⁇ max of the optical system is set to 120 °, it is desirable to narrow the upper and lower limit values of the previous condition to ⁇ 0.5 ⁇ ⁇ Zr / ⁇ Zp ⁇ 0.5.
- the reason why the conditions for the value of ⁇ Zr / ⁇ Zp change in this way is as follows.
- the depth of field of an imaging optical system is generally defined by the diameter of a circle of confusion.
- the farther away the object the smaller the image size on the image plane, and the finer resolution is required, while the closer the object, the larger the image magnification, so the farther the required resolution.
- the imaging optical system according to the present invention is designed in consideration of the use form peculiar to the capsule endoscope in which the incident angle of the light beam increases as the object distance becomes shorter and the incident angle of the light beam becomes smaller as the object distance becomes longer. . Therefore, as the shooting angle of view becomes narrower, more distant objects are included in the imaging screen, and higher resolution is required. Therefore, the condition of ⁇ Zr / ⁇ Zp needs to be narrowed.
- the imaging optical system of the present invention when the image height for an arbitrary angle of view ⁇ is Y ( ⁇ ) and the minute displacement amount of the angle of view ⁇ is ⁇ , 0.7 ⁇ (Y ( ⁇ + ⁇ ) ⁇ Y Since the relationship of ( ⁇ )) / Y ( ⁇ ) is satisfied, image distortion due to distortion is suppressed to an extent that there is no practical problem, and good imaging performance is obtained.
- a negative lens having a convex surface facing the object at a position closest to the object surface side, and at least the object side surface is aspherical. It is advantageous in terms of cost and shortening the overall length of the optical system that at least one surface of the positive lens provided at a position closest to the image surface side is aspherical.
- the convex surface directed toward the object plane side of the negative lens does not necessarily have to be a convex surface with the most protruding vertex, and for example, in the paraxial region, even if it is concave, the outer peripheral side is curved so as to approach the image plane side. It may be an aspheric surface.
- this negative lens By using such a negative lens on the most object surface side, light incident at a large angle from the periphery also emits at a small angle with respect to the optical axis due to the first negative power, and the incident angle on the aperture becomes small. As compared with an optical system having a front diaphragm, a light amount loss due to the thickness of the diaphragm can be suppressed.
- Behind this negative lens is a positive lens group consisting of a plurality of lenses and having a positive power as a whole. The positive lens group is located closest to the object side and closest to the image plane. If the lens to be configured is a positive lens and the positive power is dispersed, the curvature of field can be easily adjusted while correcting the aberration generated in the negative lens.
- the entire subject can be kept within the depth of field by widening the angle of view and aligning the image plane in the vicinity of the imaging plane perpendicular to the optical axis over the entire angle of view.
- a clear lesion image without blur can be obtained at any position of the throat.
- FIG. 2 is a cross-sectional view when the capsule endoscope of FIG. 1 is rotated 90 degrees around the optical axis. It is a top view which shows arrangement
- [Formula 1] (A) is an explanatory diagram showing a concentric circle attached on a concave hemispherical object, and (B) to (E) are images showing the image when the concentric circle of (A) is imaged.
- 1 is a lens configuration diagram illustrating an imaging optical system of Example 1.
- FIG. FIG. 6 is an aberration diagram of the image pickup optical system according to the first example. 3 is a graph showing distortion of the imaging optical system of Example 1.
- FIG. 6 is a lens configuration diagram illustrating an imaging optical system of Example 2.
- FIG. 6 is an aberration diagram of the image pickup optical system according to the second embodiment.
- 7 is a graph showing distortion of the imaging optical system of Example 2.
- 6 is a lens configuration diagram illustrating an imaging optical system of Example 3.
- FIG. 10 is an aberration diagram of the image pickup optical system according to Example 3.
- FIG. 10 is a graph showing distortion of the imaging optical system of Example 3.
- 6 is a lens configuration diagram illustrating an imaging optical system of Example 4.
- FIG. 10 is an aberration diagram of the image pickup optical system according to the fourth embodiment. 10 is a graph showing distortion of the imaging optical system of Example 4.
- FIG. 6 is a lens configuration diagram illustrating an imaging optical system of Example 5.
- 10 is an aberration diagram of the image pickup optical system according to the fifth embodiment. 10 is a graph showing distortion of the imaging optical system of Example 5. 10 is a lens configuration diagram illustrating an imaging optical system according to Example 6. FIG. FIG. 10 is an aberration diagram of the image pickup optical system according to the sixth embodiment. 10 is a graph showing distortion of the imaging optical system of Example 6. FIG. 10 is a lens configuration diagram illustrating an imaging optical system of Example 7. FIG. 10 is an aberration diagram of the image pickup optical system according to the seventh embodiment. 10 is a graph showing distortion of the imaging optical system according to Example 7. 10 is a lens configuration diagram illustrating an imaging optical system according to Example 8. FIG. FIG. 10 is an aberration diagram of the image pickup optical system according to the eighth embodiment.
- FIG. 10 is a graph showing distortion of the imaging optical system according to Example 8.
- 10 is a lens configuration diagram illustrating an imaging optical system according to Example 9.
- FIG. 10 is an aberration diagram of the image pickup optical system according to the ninth embodiment.
- 14 is a graph showing distortion of the imaging optical system according to Example 9.
- FIG. 11 is a lens configuration diagram illustrating an imaging optical system according to Example 10.
- FIG. 10 is an aberration diagram of the image pickup optical system according to the tenth embodiment.
- 10 is a graph showing distortion of the imaging optical system according to Example 10.
- 12 is a lens configuration diagram illustrating an imaging optical system according to Example 11.
- FIG. 10 is an aberration diagram of the image pickup optical system according to the eleventh embodiment.
- 14 is a graph showing distortion of the image pickup optical system according to the eleventh embodiment.
- FIG. 14 is a lens configuration diagram illustrating an image pickup optical system according to Example 12.
- FIG. FIG. 14 is an aberration diagram of the image pickup optical system according to the twelfth embodiment.
- 14 is a graph showing distortion of the image pickup optical system according to the twelfth embodiment.
- 14 is a lens configuration diagram illustrating an image pickup optical system according to Example 13.
- FIG. FIG. 14 is an aberration diagram of the image pickup optical system according to the thirteenth embodiment.
- 14 is a graph showing distortion of the imaging optical system according to Example 13.
- FIG. 16 is a lens configuration diagram illustrating an imaging optical system according to Example 14;
- FIG. 16 is an aberration diagram of the image pickup optical system according to the fourteenth embodiment.
- 22 is a graph showing distortion of the image pickup optical system according to the fourteenth embodiment.
- FIG. 16 is a lens configuration diagram illustrating an image pickup optical system according to a fifteenth embodiment.
- FIG. 16 is an aberration diagram of the image pickup optical system according to the fifteenth embodiment. 25
- the capsule endoscope 10 has a capsule shape having a diameter of about 10 mm and a length of about several tens of millimeters so that the subject can easily swallow it.
- the inside of the stomach or intestine is imaged at regular intervals from when the subject swallows to when the subject is discharged from the body.
- the imaging optical system of the present invention incorporated in the capsule endoscope 10 assumes that the object surface (subject surface) 12 is a concave hemispherical surface, and favorably sets the object surface to a plane perpendicular to the optical axis. It has a function to form an image.
- the object surface 12 is not necessarily an accurate concave hemispherical surface, and may be another concave curved surface shape.
- FIG. 2 shows a state in which the capsule endoscope 10 is rotated by 90 ° around the central axis.
- the capsule endoscope 10 has a capsule 13 in which the front end side of an opaque capsule body 22 closed at the rear end side is closed with a dome-shaped transparent cover 23, An area-type imaging device 14 whose front surface is covered with a cover glass 21, first to fourth LEDs (Light Emitting Diodes) 15 to 18 serving as illumination light sources, and an imaging optical system 20 are incorporated.
- the capsule 13 further stores a battery that drives the image sensor 14 and an antenna (all not shown) that transmits an image signal obtained by the image sensor 14 to a receiver attached around the subject. Yes.
- the imaging optical system 20 forms an image of subject light obtained through the transparent cover 23 having no power on the imaging surface of the imaging device 14.
- FIG. 3 shows a state in which the capsule endoscope 10 is viewed from the front through the transparent cover 23.
- the first to fourth LEDs 15 to 18 are provided around the imaging optical system 20 with a pitch of about 90 °.
- the second and fourth LEDs 16 and 18 are shifted from the first and third LEDs 15 and 17 toward the imaging element 14 with respect to the direction of the optical axis XP of the imaging optical system 20.
- the first and third LEDs 15 and 17 are provided so that their illumination optical axes X1 and X3 are parallel to the optical axis XP of the imaging optical system 20, and mainly the center of the subject 12 and the center of the subject 12 including its periphery. Illuminate the part.
- the second and fourth LEDs 16 and 18 are provided such that the illumination optical axes X2 and X4 are inclined at a constant angle with respect to the optical axis XP of the imaging optical system 20, and mainly the central portion of the subject 12. Illuminate the peripheral portion of the subject 12 including from to the end. Thereby, it is possible to irradiate illumination light uniformly over almost the entire subject 12 having a concave hemispherical surface. In addition, flare does not occur even if light is emitted from the LEDs 15 to 18 in the capsule 13.
- the imaging optical system 20 includes a first lens L1, an aperture stop S6, a second lens L2, a third lens L3, a fourth lens L4, and a fifth lens L5 in this order from the subject 12 side. ing.
- the LEDs 15 to 18 are not shown, and the surface of the transparent cover 23 is indicated by a two-dot chain line.
- the imaging optical system 20 has a negative curvature of field, and has a function of favorably imaging the concave object surface 12 on an imaging surface perpendicular to the optical axis Xp.
- the imaging optical system 20 is basically composed of a negative lens in which the first lens L1 has a convex surface facing the object surface 12, and preferably at least on the object side of the first lens L1.
- the surface is designed as an aspheric surface, and any surface of the fifth lens L5 is also an aspheric surface.
- the imaging performance is preferable as imaging performance.
- the maximum angle of view (2 ⁇ max) of the imaging optical system 20 is 120 ° or more, it is designed to satisfy the following [Equation 1].
- ⁇ Zr and ⁇ Zp in the equation (1) represent the following when the maximum field angle of the imaging optical system 20 is 2 ⁇ max and the maximum half field angle is ⁇ max.
- ⁇ Zr difference between the real image plane position with respect to the light flux of 2 ⁇ max and the real image plane position with respect to the light flux of ⁇ max
- ⁇ Zp a plane passing through the intersection P1 of the subject 12 and the principal ray of 2 ⁇ max and perpendicular to the optical axis XP is defined as the virtual object plane 24
- the paraxial image plane position when the virtual object plane 25 is a plane that passes through the intersection P2 of the subject 12 and the principal ray of ⁇ max and is perpendicular to the optical axis XP.
- the imaging optical system 20 When the imaging optical system 20 satisfies the formula [1], the curvature of field is sufficiently corrected, and the entire object surface 12 including the central portion and the peripheral portion of the concave hemispherical surface is covered by the imaging optical system 20. Within the depth of field. Therefore, since a clear image in which both the central portion and the peripheral portion of the image are in focus can be captured, even if there is a lesion portion in the peripheral portion of the image, the lesion portion can be reliably detected.
- the real image plane due to the 2 ⁇ max light beam and the real image surface due to the ⁇ max light beam are greatly shifted in the optical axis Xp direction, so that both of them are well imaged on the imaging plane perpendicular to the optical axis Xp. Therefore, in the imaging optical system 20 having the maximum field angle (2 ⁇ max) of 120 ° or more, it is preferable to satisfy the condition of ABS ( ⁇ Zr / ⁇ Zp) ⁇ 0.5. In addition, ABS represents the absolute value of the value in ().
- the maximum angle of view (2 ⁇ max) of the imaging optical system 20 is further expanded and is set to 135 ° or more, the value of ABS ( ⁇ Zr / ⁇ Zp) can be relaxed. It is also possible to design within the range to satisfy.
- the imaging optical system 20 has the following when the image height at the angle of view ⁇ is Y ( ⁇ ), regardless of whether the maximum angle of view (2 ⁇ max) is 120 ° or more or 135 ° or more. It is designed to satisfy the formula [3]. Note that [Equation 3] may be satisfied under a condition where the angle of view is 45 ° or less.
- Y ( ⁇ + ⁇ ) ⁇ Y ( ⁇ ) in [Equation 3] is an image height Y ( ⁇ + ⁇ ) when the angle of view is slightly changed by ⁇ from ⁇ , and an image when the angle of view is ⁇ . The difference from high Y ( ⁇ ) is shown.
- “Y ( ⁇ )” in [Equation 3] indicates the image height Y ( ⁇ ) when the field angle is slightly changed from 0 ° by ⁇ , and the image height when the field angle is 0 °.
- (Y ( ⁇ + ⁇ ) ⁇ Y ( ⁇ )) / Y ( ⁇ ) is a distortion index Q, and the values of Q are “1.0”, “0.7”, “0.5”, “0.
- the imaging optical system 20 is designed to be “3”, the degree of distortion appearing in an image obtained by each imaging optical system is evaluated.
- a plurality of circles (concentric circles) 30a to 30e having radii of “r”, “2r”, “3r”, “4r”, and “5r” are arranged at the center.
- the object plane 12 is set so as to coincide with the optical axis Xp, and these concentric circles are imaged through the respective imaging optical systems 20.
- the degree of distortion in the peripheral portion of the image is evaluated based on how the distance between the concentric circles in the peripheral portion of the image obtained by imaging changes.
- the interval between the circles on the image is the distance r, as is the interval between the plurality of circles 30a to 30e provided on the subject 12.
- the fact that the interval between the circles in the central portion of the image is the same as the interval between the circles in the peripheral portion of the image indicates that no distortion has occurred in the peripheral portion of the image. Therefore, if the subject's body is imaged by the capsule endoscope 10 incorporating such an imaging optical system 20, almost no distortion appears in the image projected on the peripheral portion of the image, and the lesion area is not affected. Visual recognition becomes easy.
- the interval between the circles in the central portion of the image is slightly larger than r
- the interval between the circles in the peripheral portion of the image is slightly smaller than r.
- the image is not observed as a large distortion in the central portion and the peripheral portion, and even when this imaging optical system 20 is used, it is practically satisfactory in terms of image diagnosis. It can be said that it is within the range.
- the value of the distortion index Q that is, the value of (Y ( ⁇ + ⁇ ) ⁇ Y ( ⁇ )) / Y ( ⁇ ) is It can be seen that if the imaging optical system is designed to exceed 0.7, the distortion in the peripheral portion of the image can be suppressed to a level that does not cause a problem in practice. By suppressing the distortion in this way, it is possible to reliably prevent oversight of the lesion even in the peripheral part of the image, and it is possible to improve the reliability of the image diagnosis.
- the value of the distortion index Q is preferably larger than 0.7 and smaller than 1.3, and more preferably in the range of 0.8 ⁇ Q ⁇ 1.2.
- the imaging optical system 20 is configured with five lenses of the first to fifth lenses, the entire object plane 12 including the central portion and the peripheral portion can be accommodated within the depth of field of the imaging optical system 20. . Therefore, a clear image in which the central portion and the peripheral portion are in focus can be obtained, and distortion in the peripheral portion of the image is hardly a problem.
- an imaging optical system 20 is not necessarily limited to a five-lens configuration, and substantially the same effect can be obtained even when the imaging optical system 20 is configured by four lenses of the first to fourth lenses.
- the imaging optical system of the present invention is an imaging optical system for a capsule endoscope that can control the position in the body cavity and the posture of imaging in accordance with a control signal from the outside after being swallowed into the body cavity. Can also be used.
- the imaging optical system 20 of the first embodiment includes five first to fifth lenses L1 to L5 and an aperture stop S6. From the concave hemispherical object surface 12 side in the capsule 13.
- the first lens L1, the aperture stop S6, the second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5 are arranged in this order.
- the third lens L3 and the fourth lens L4 are bonded lenses.
- the surface of the image pickup optical system 20 is expressed by assigning a surface number Si toward the image surface side with the object surface S1, including the transparent cover 23, the surface of the transparent cover 23 is S2, and the back surface is S3. It becomes. Thereafter, the surface numbers Si are assigned in order from the front and back surfaces of the first lens L1 to the fifth lens L5 to the back surface S15 of the cover glass 21. Note that the back surface of the third lens L3 and the front surface of the fourth lens L4 are common on the cemented surface S10, and the back surface S15 of the cover glass 21 coincides with the imaging surface of the image sensor 14.
- the distance (surface distance) between the surface Si and the surface Si + 1 with respect to the optical axis direction of the imaging optical system 20 is expressed as Di
- the surface distance between the surface S1 and the surface S2 is D1
- the distance is expressed in the same manner up to D2 and the surface distance D14 between the surface S14 and the surface S15.
- the imaging optical system 20 is designed based on the lens data shown in Table 1 below.
- OBJ concave hemispherical object surface 12
- aperture is the aperture stop S 6
- IMG is the imaging surface of the image sensor 14
- curvature radius is the radius of curvature of each surface Si ( mm)
- surface spacing is the surface spacing Di (mm)
- Nd is the refractive index for the d-line (wavelength 587.6 nm)
- ⁇ d is the Abbe number
- f is the imaging optical system.
- the focal length of the entire 20 “Fno” represents the F value F of the imaging optical system 20
- 2 ⁇ max represents the maximum angle of view.
- both surfaces S4 and S5 of the first lens, both surfaces S7 and S8 of the second lens, and both surfaces S12 and S13 of the fifth lens are aspherical surfaces.
- Table 2 shows the conic constant K and the aspherical constant Ai of the surfaces S4, S5, S7, S8, S12, and S13. In Examples 2 to 15 described later, the expression of [Expression 4] that determines the notation of the lens data and the shape of the aspherical surface is also used in common.
- FIG. 7 shows spherical aberration, astigmatism, and lateral chromatic aberration when the object surface 12 is imaged on the imaging surface by the imaging optical system 20 through the transparent cover 23 and the cover glass 21 in front of the imaging element.
- the d-line (wavelength 587.6 nm) is the solid line
- the F-line (wavelength 486.13 nm) is the first broken line
- the C-line (wavelength 656.27 nm) is the length of each line. It is indicated by a second broken line that is larger than the first broken line.
- Astigmatism is indicated by a solid line in the sagittal direction and by a first broken line in the tangential direction.
- the lateral chromatic aberration is indicated by the first broken line for the F line, and by the second broken line whose length is longer than the first broken line for the C line.
- the object surface 12 is imaged on the imaging surface through the transparent cover 23 and the cover glass 21, and the spherical aberration, astigmatism, and lateral chromatic aberration are similarly described. Is also common.
- ⁇ Zr is ⁇ 0.001 and ⁇ Zp is 0.020. Therefore, in this imaging optical system 20 having a maximum field angle 2 ⁇ max of 120 °, ⁇ Zr / ⁇ Zp is not only in [Expression 2] but also in [Expression 1], so that the field curvature is sufficiently corrected,
- the entire object plane 12 including the central portion and the peripheral portion is accommodated within the depth of field of the imaging optical system 20. As a result, a clear image in which both the central portion and the peripheral portion of the image are in focus is projected, and even if there is a lesion portion in the peripheral portion of the image, the lesion portion can be reliably detected.
- (Y ( ⁇ + ⁇ ) ⁇ Y ( ⁇ )) / Y ( ⁇ ) is larger than 0.7 in the entire range of the half field angle ⁇ . Therefore, the imaging optical system 20 satisfies the formula [3], and can suppress distortion in the peripheral portion of the image. Therefore, even if a lesioned part is projected in the peripheral part of the image, the lesioned part is not distorted so as to be overlooked, so that the lesioned part can be reliably detected.
- the imaging optical system 30 includes four first to fourth lenses L1 to L4 and an aperture stop S8.
- the first lens L1, the second lens L2, the aperture stop S8, the third lens L3, and the fourth lens L4 are arranged in this order.
- the imaging optical system 30 has lens data shown in [Table 3] below.
- both surfaces S4 and S5 of the first lens, both surfaces S6 and S7 of the second lens, both surfaces S9 and S10 of the third lens, and both surfaces S11 and S12 of the fourth lens are not. It is a spherical surface.
- Table 4 shows the conic constant K and the aspherical constant Ai of these surfaces S4, S5, S6, S7, S9, S10, S11, and S12.
- FIG. 10 shows spherical aberration, astigmatism, and lateral chromatic aberration of the imaging optical system.
- the maximum field angle of the imaging optical system 30 of the second embodiment is 130 °, ⁇ Zr is ⁇ 0.005, and ⁇ Zp is 0.028. Therefore, ⁇ Zr / ⁇ Zp is ⁇ 0.167, which is within the range of [Equation 1] as well as [Equation 2]. Therefore, the curvature of field is sufficiently corrected, and the entire object plane 12 including the central portion and the peripheral portion is accommodated within the depth of field of the imaging optical system 30. As a result, a clear image in which both the central portion and the peripheral portion of the image are in focus is projected, and even if there is a lesion portion in the peripheral portion of the image, the lesion portion can be reliably detected.
- (Y ( ⁇ + ⁇ ) ⁇ Y ( ⁇ )) / Y ( ⁇ ) is larger than 0.7 in the entire range of the half angle of view ⁇ . Therefore, the imaging optical system 30 is within the range of the equation [3], and distortion in the peripheral portion of the image can be suppressed. Therefore, even if a lesioned part is projected in the peripheral part of the image, the lesioned part is not distorted so as to be overlooked, so that the lesioned part can be reliably detected.
- the imaging optical system 40 includes five first to fifth lenses L1 to L5 and an aperture stop S6.
- the first lens L1, the aperture stop S6, the second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5 are arranged in this order.
- the lens data of the imaging optical system 40 is as shown in Table 5 below.
- both surfaces S4 and S5 of the first lens L1 and both surfaces S13 and S14 of the fifth lens L5 are aspheric.
- Table 6 shows the conic constant K and the aspherical constant Ai of these surfaces S4, S5, S13, and S14.
- FIG. 13 shows the spherical aberration, astigmatism, and lateral chromatic aberration of the imaging optical system 40 in the same manner.
- ⁇ Zr is 0.003 and ⁇ Zp is 0.036.
- the ⁇ Zr / ⁇ Zp value of the imaging optical system 40 having the maximum field angle 2 ⁇ max of 130 ° is 0.081, which is not only in the range of [Numerical equation 2] but also in the range of [Numerical equation 1]. Therefore, the curvature of field is sufficiently corrected, and the entire subject 12 including the central portion and the peripheral portion of the subject 12 is accommodated within the depth of field of the imaging lens 40. Further, as shown in FIG.
- Example 4 The imaging optical system 50 of Example 4 is as shown in FIG. 15, and in order from the object plane 12, the first lens L1, the second lens L2, the aperture stop S8, the third lens L3, the fourth lens L4, and the fifth lens L5.
- the third lens L3 and the fourth lens L4 are bonded lenses.
- Table 7 shows lens data
- Table 8 shows data for each aspherical surface with * in the surface number column.
- the maximum field angle of this imaging optical system 50 is 125 °, and its spherical aberration, astigmatism, and lateral chromatic aberration are shown in FIG. ⁇ Zr is ⁇ 0.005, ⁇ Zp is 0.018, and ⁇ Zr / ⁇ Zp is ⁇ 0.279. Therefore, not only the range of [Numerical equation 2] but also the range of [Numerical equation 1] is satisfied. Therefore, the curvature of field is sufficiently corrected, and the entire subject 12 including the central portion and the peripheral portion of the subject 12 is accommodated within the depth of field of the imaging lens 50.
- Example 5 The configuration of the imaging optical system 60 of Example 5 is shown in FIG. Similarly to the above embodiment, Table 9 shows lens data, Table 10 shows aspheric data used in surface numbers S4, S5, S11, and S12, and FIG. 19 shows spherical aberration, astigmatism, and lateral chromatic aberration.
- the imaging optical system 60 of Example 5 has a maximum field angle of 170 °, ⁇ Zr of ⁇ 0.018, and ⁇ Zp of 0.202. Since ⁇ Zr / ⁇ Zp is ⁇ 0.088, it is within the range of [Equation 1] as well as [Equation 2]. Also, as shown in FIG. 20, (Y ( ⁇ + ⁇ ) ⁇ Y ( ⁇ )) / Y ( ⁇ ) is larger than 0.7. Therefore, in the imaging optical system 60, the condition of [Equation 3] is satisfied, and the image of the object plane 12 including the central portion and the peripheral portion can be well accommodated within the depth of field, and the peripheral portion is also large. Good image formation can be obtained without distortion.
- Example 6 The configuration of the imaging optical system 70 of Example 6 is shown in FIG. Similarly to the above embodiment, Table 11 shows lens data, Table 12 shows aspheric data, and FIG. 22 shows spherical aberration, astigmatism, and lateral chromatic aberration.
- ⁇ Zr In this imaging optical system 70 with a maximum field angle of 170 °, ⁇ Zr is ⁇ 0.015, ⁇ Zp is 0.186, and ⁇ Zr / ⁇ Zp is ⁇ 0.080. Satisfies. As shown in FIG. 23, (Y ( ⁇ + ⁇ ) ⁇ Y ( ⁇ )) / Y ( ⁇ ) is larger than 0.7. Therefore, also in this imaging optical system 70, the condition of [Equation 3] is satisfied, and the image of the object plane 12 including the central portion and the peripheral portion can be satisfactorily within the depth of field, and the peripheral portion is also large. Good image formation can be obtained without distortion.
- Example 7 The configuration of the imaging optical system 80 of Example 7 is shown in FIG. As in the above example, Table 13 shows lens data, Table 14 shows aspheric data, and FIG. 25 shows spherical aberration, astigmatism, and lateral chromatic aberration.
- FIG. 27 shows the configuration of the imaging optical system 90 of the eighth embodiment.
- Table 15 shows lens data
- Table 16 shows aspheric data
- FIG. 28 shows spherical aberration, astigmatism, and lateral chromatic aberration.
- the imaging optical system 90 has a maximum field angle of 170 °, ⁇ Zr of ⁇ 0.031, and ⁇ Zp of 0.133. Since ⁇ Zr / ⁇ Zp is ⁇ 0.235, it is within the range of [Equation 2] and [Equation 1]. As shown in FIG. 29, (Y ( ⁇ + ⁇ ) ⁇ Y ( ⁇ )) / Y ( ⁇ ) is larger than 0.7. Therefore, in this imaging optical system 80, the condition of [Equation 3] is satisfied, and the image of the object plane 12 including the central portion and the peripheral portion can be well within the depth of field, and the peripheral portion is also large. Good image formation can be obtained without distortion.
- FIG. 30 shows the configuration of the imaging optical system 100 of the ninth embodiment.
- Table 17 shows lens data
- Table 18 shows aspheric data
- FIG. 31 shows spherical aberration, astigmatism, and lateral chromatic aberration.
- this imaging optical system 90 has a maximum angle of view of 170 °, ⁇ Zr is 0.036, ⁇ Zp is 0.168, and ⁇ Zr / ⁇ Zp is 0.215, the range of [Equation 1] as well as [Equation 2] It is also within. Also, as shown in FIG. 32, (Y ( ⁇ + ⁇ ) ⁇ Y ( ⁇ )) / Y ( ⁇ ) is larger than 0.7. Therefore, in this imaging optical system 80, the condition of [Equation 3] is satisfied, and the image of the object plane 12 including the central portion and the peripheral portion can be well within the depth of field, and the peripheral portion is also large. Good image formation can be obtained without distortion.
- Example 10 The configuration of the imaging optical system 110 of Example 10 is shown in FIG. As in the above embodiment, Table 19 shows lens data, Table 20 shows aspheric data, and FIG. 34 shows spherical aberration, astigmatism, and lateral chromatic aberration.
- the imaging optical system 110 has a maximum field angle of 155 °, ⁇ Zr of ⁇ 0.020, and ⁇ Zp of 0.069. Since ⁇ Zr / ⁇ Zp is ⁇ 0.295, it is within the range of [Equation 1] as well as [Equation 2]. As shown in FIG. 35, (Y ( ⁇ + ⁇ ) ⁇ Y ( ⁇ )) / Y ( ⁇ ) is larger than 0.7. Therefore, the condition of [Equation 3] is also satisfied in this imaging optical system 80, and the image of the object plane 12 including the central portion and the peripheral portion can be satisfactorily within the depth of field, and distortion is also suppressed. And good imaging performance can be obtained.
- Example 11 The configuration of the imaging optical system 120 of Example 11 is shown in FIG. As in the above example, Table 21 shows lens data, Table 22 shows aspheric data, and FIG. 37 shows spherical aberration, astigmatism, and lateral chromatic aberration. Similarly, FIG. 38 shows a graph showing the degree of distortion based on the value of (Y ( ⁇ + ⁇ ) ⁇ Y ( ⁇ )) / Y ( ⁇ ).
- Example 12 The configuration of the imaging optical system 130 of Example 12 is shown in FIG. As in the above example, Table 23 shows lens data, Table 24 shows aspheric data, and FIG. 40 shows spherical aberration, astigmatism, and lateral chromatic aberration. Similarly, FIG. 41 shows a graph representing the degree of distortion based on the value of (Y ( ⁇ + ⁇ ) ⁇ Y ( ⁇ )) / Y ( ⁇ ).
- the maximum field angle of the imaging optical system 130 is 150 °, ⁇ Zr is 0.078, ⁇ Zp is 0.069, and ⁇ Zr / ⁇ Zp is 1.120. Since the maximum angle of view of the imaging optical system 130 is 135 ° or more, it is sufficient if [Equation 2] is satisfied. Therefore, the image of the object plane 12 can be kept within the depth of field for both the central portion and the peripheral portion. Further, as shown in FIG. 41, (Y ( ⁇ + ⁇ ) ⁇ Y ( ⁇ )) / Y ( ⁇ ) is larger than 0.7 and satisfies the condition of [Equation 3]. It can be suppressed to a certain extent.
- Example 13 The configuration of the imaging optical system 140 of Example 13 is shown in FIG. As in the above example, Table 25 shows lens data, Table 26 shows aspheric data, and FIG. 43 shows spherical aberration, astigmatism, and lateral chromatic aberration. Similarly, FIG. 44 shows a graph showing the degree of distortion based on the value of (Y ( ⁇ + ⁇ ) ⁇ Y ( ⁇ )) / Y ( ⁇ ).
- ⁇ Zr is ⁇ 0.036
- ⁇ Zp is 0.034
- ⁇ Zr / ⁇ Zp is ⁇ 1.048. Since the maximum field angle (2 ⁇ max) of the imaging optical system 140 is 140 °, it is only necessary to satisfy [Equation 2]. Therefore, the image of the object plane 12 can be kept within the depth of field for both the central portion and the peripheral portion. Further, as shown in FIG. 44, (Y ( ⁇ + ⁇ ) ⁇ Y ( ⁇ )) / Y ( ⁇ ) is larger than 0.7 and satisfies the condition of [Equation 3], and thus easily occurs in the peripheral portion. Distortion can be suppressed to the extent that there is no problem.
- Example 14 The configuration of the imaging optical system 150 of Example 14 is shown in FIG. As in the above embodiment, Table 27 shows lens data, Table 28 shows aspheric data, and FIG. 46 shows spherical aberration, astigmatism, and lateral chromatic aberration. Similarly, FIG. 47 shows a graph representing the degree of distortion based on the value of (Y ( ⁇ + ⁇ ) ⁇ Y ( ⁇ )) / Y ( ⁇ ).
- ⁇ Zr is ⁇ 0.034
- ⁇ Zp is 0.060
- ⁇ Zr / ⁇ Zp is ⁇ 0.566. Since the maximum angle of view (2 ⁇ max) of the imaging optical system 150 is 150 °, it is sufficient if [Equation 2] is satisfied. Therefore, the image of the object plane 12 can be kept within the depth of field for both the central portion and the peripheral portion. Further, as shown in FIG. 47, (Y ( ⁇ + ⁇ ) ⁇ Y ( ⁇ )) / Y ( ⁇ ) is larger than 0.7 and satisfies the condition of [Equation 3], and thus easily occurs in the peripheral portion. Distortion can be suppressed to the extent that there is no problem.
- Example 15 The configuration of the imaging optical system 160 of Example 15 is shown in FIG. As in the above example, Table 29 shows lens data, Table 30 shows aspheric data, and FIG. 49 shows spherical aberration, astigmatism, and lateral chromatic aberration. Similarly, FIG. 50 shows a graph showing the degree of distortion based on the value of (Y ( ⁇ + ⁇ ) ⁇ Y ( ⁇ )) / Y ( ⁇ ).
- ⁇ Zr is ⁇ 0.018
- ⁇ Zp is 0.202
- ⁇ Zr / ⁇ Zp is ⁇ 0.088.
- the maximum field angle (2 ⁇ max) of the imaging optical system 160 is 170 °
- both [Equation 1] and [Equation 2] are satisfied. Therefore, the image of the object plane 12 can be kept within the depth of field for both the central portion and the peripheral portion.
- (Y ( ⁇ + ⁇ ) ⁇ Y ( ⁇ )) / Y ( ⁇ ) is larger than 0.7 and satisfies the condition of [Equation 3], and thus easily occurs in the peripheral portion. Distortion can be suppressed to the extent that there is no problem.
- the real image plane position for the 2 ⁇ max light beam is greatly shifted to the object side relative to the real image surface position for the ⁇ max light beam, and a part of the image obtained by the imaging is out of the depth of field, so that good image formation is achieved. Can't get.
- the real image plane position for the 2 ⁇ max light beam is greatly shifted to the object side relative to the real image surface position for the ⁇ max light beam, and a part of the image obtained by the imaging is out of the depth of field, so that good image formation is achieved. Can't get.
- the real image plane position for the 2 ⁇ max light beam is greatly shifted to the object side relative to the real image surface position for the ⁇ max light beam, and a part of the image obtained by the imaging is out of the depth of field, so that good image formation is achieved. Can't get.
Landscapes
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Physics & Mathematics (AREA)
- Surgery (AREA)
- Optics & Photonics (AREA)
- Medical Informatics (AREA)
- Animal Behavior & Ethology (AREA)
- Radiology & Medical Imaging (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- Engineering & Computer Science (AREA)
- Biomedical Technology (AREA)
- Heart & Thoracic Surgery (AREA)
- Biophysics (AREA)
- Molecular Biology (AREA)
- Pathology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- General Physics & Mathematics (AREA)
- Astronomy & Astrophysics (AREA)
- Endoscopes (AREA)
- Lenses (AREA)
- Instruments For Viewing The Inside Of Hollow Bodies (AREA)
- Measurement Of The Respiration, Hearing Ability, Form, And Blood Characteristics Of Living Organisms (AREA)
Abstract
Description
ΔZr:2ωmaxの光束に対する実像面位置と、ωmaxの光束に対する実像面位置との差
ΔZp:被写体12と2ωmaxの主光線との交点P1を通り、光軸XPに垂直な平面を仮想物体面24としたときの近軸像面位置と、被写体12とωmaxの主光線との交点P2を通り、光軸XPに垂直な平面を仮想物体面25としたときの近軸像面位置との差
図6に示すように、実施例1の撮像光学系20は5枚の第1~第5レンズL1~L5と開口絞りS6とを備え、カプセル13内において、凹状半球面の物体面12側から、第1レンズL1、開口絞りS6、第2レンズL2、第3レンズL3、第4レンズL4、第5レンズL5の順に配置されている。第3レンズL3と第4レンズL4とは貼り合わせレンズとなっている。
図9に示すように、実施例2の撮像光学系30は4枚の第1~第4レンズL1~L4と開口絞りS8とを備え、カプセル13内において、凹状半球面の物体面12側から、第1レンズL1、第2レンズL2、開口絞りS8、第3レンズL3、第4レンズL4の順に配置されている。この撮像光学系30は、以下の[表3]に示すレンズデータとなっている。
図12に示すように、実施例3の撮像光学系40は5枚の第1~第5レンズL1~L5と開口絞りS6とを備え、カプセル13内において、凹状半球面の被写体12側から、第1レンズL1、開口絞りS6、第2レンズL2、第3レンズL3、第4レンズL4、第5レンズL5の順に配置されている。この撮像光学系40のレンズデータは次の表5のとおりである。
実施例4の撮像光学系50は図15に示すとおりで、物体面12から順に、第1レンズL1、第2レンズL2、開口絞りS8、第3レンズL3、第4レンズL4、第5レンズL5と配置され、第3レンズL3と第4レンズL4とは貼り合わせレンズとなっている。これまでの実施例と同様に、表7にレンズデータ、表8に面番号欄に*が付されたそれぞれの非球面のデータを示す。
実施例5の撮像光学系60の構成を図18に示す。上記実施例と同様に、表9にレンズデータ、表10に面番号S4,S5,S11,S12で用いられている非球面のデータ、図19に球面収差、非点収差、倍率色収差を示す。
実施例6の撮像光学系70の構成を図21に示す。上記実施例と同様に、表11にレンズデータ、表12に非球面のデータ、図22に球面収差、非点収差、倍率色収差を示す。
実施例7の撮像光学系80の構成を図24に示す。上記実施例と同様に、表13にレンズデータ、表14に非球面のデータ、図25に球面収差、非点収差、倍率色収差を示す。
実施例8の撮像光学系90の構成を図27に示す。上記実施例と同様に、表15にレンズデータ、表16に非球面のデータ、図28に球面収差、非点収差、倍率色収差を示す。
実施例9の撮像光学系100の構成を図30に示す。上記実施例と同様に、表17にレンズデータ、表18に非球面のデータ、図31に球面収差、非点収差、倍率色収差を示す。
実施例10の撮像光学系110の構成を図33に示す。上記実施例と同様に、表19にレンズデータ、表20に非球面のデータ、図34に球面収差、非点収差、倍率色収差を示す。
実施例11の撮像光学系120の構成を図36に示す。上記実施例と同様に、表21にレンズデータ、表22に非球面のデータ、図37に球面収差、非点収差、倍率色収差を示す。また、同様に(Y(ω+Δω)-Y(ω))/Y(Δω)の値に基づくディストーションの程度を表すグラフを図38に示す。
実施例12の撮像光学系130の構成を図39に示す。上記実施例と同様に、表23にレンズデータ、表24に非球面のデータ、図40に球面収差、非点収差、倍率色収差を示す。また、同様に(Y(ω+Δω)-Y(ω))/Y(Δω)の値に基づくディストーションの程度を表すグラフを図41に示す。
実施例13の撮像光学系140の構成を図42に示す。上記実施例と同様に、表25にレンズデータ、表26に非球面のデータ、図43に球面収差、非点収差、倍率色収差を示す。また、同様に(Y(ω+Δω)-Y(ω))/Y(Δω)の値に基づくディストーションの程度を表すグラフを図44に示す。
実施例14の撮像光学系150の構成を図45に示す。上記実施例と同様に、表27にレンズデータ、表28に非球面のデータ、図46に球面収差、非点収差、倍率色収差を示す。また、同様に(Y(ω+Δω)-Y(ω))/Y(Δω)の値に基づくディストーションの程度を表すグラフを図47に示す。
実施例15の撮像光学系160の構成を図48に示す。上記実施例と同様に、表29にレンズデータ、表30に非球面のデータ、図49に球面収差、非点収差、倍率色収差を示す。また、同様に(Y(ω+Δω)-Y(ω))/Y(Δω)の値に基づくディストーションの程度を表すグラフを図50に示す。
特許文献2の「添付光学系データ1」に示される撮像光学系で、光学的なパワーを持たない透明カバーを通して、撮像レンズの入射瞳位置を中心とした球面状の物体面を撮像すると、ΔZrは-0.109となり、ΔZpは0.016となる。したがって、この撮像光学系では最大画角が120°未満であるにもかかわらず、ΔZr/ΔZpは-6.683となって[数1]の範囲外となる。そのため、2ωmaxの光束に対する実像面位置が、ωmaxの光束に対する実像面位置よりも物体側に大きくずれてしまい、撮像により得られる画像の一部が被写界深度外となって良好な結像を得ることができない。
同様に、特許文献2の「添付光学系データ2」に示される撮像光学系で、光学的なパワーを持たない透明カバーを通して、撮像レンズの入射瞳位置を中心とした球面状の物体面を撮像すると、ΔZrは-0.010、ΔZpは0.017となる。したがって、最大画角が120°未満であるのにΔZr/ΔZpは-0.594となって、やはり[数1]の範囲外となる。そのため、2ωmaxの光束に対する実像面位置が、ωmaxの光束に対する実像面位置よりも物体側に大きくずれてしまい、撮像により得られる画像の一部が被写界深度外となって良好な結像を得ることができない。
同様に、特許文献2の「添付光学系データ3」に示される撮像光学系で、光学的なパワーを持たない透明カバーを通して、撮像レンズの入射瞳位置を中心とした球面状の物体面を撮像すると、ΔZrは-0.158、ΔZpは0.015となる。したがって、最大画角が120°未満であるのにΔZr/ΔZpは-10.849となって[数1]の範囲外である。そのため、2ωmaxの光束に対する実像面位置が、ωmaxの光束に対する実像面位置よりも物体側に大きくずれてしまい、撮像により得られる画像の一部が被写界深度外となって良好な結像を得ることができない。
同様にして特許文献2の「添付光学系データ4」に示される撮像光学系を用いた場合でも、ΔZrは-0.024、ΔZpは0.035であり、ΔZr/ΔZpは-0.687となる。最大画角が120°未満であっても[数1]の範囲外になり、2ωmaxの光束に対する実像面位置が、ωmaxの光束に対する実像面位置よりも物体側に大きくずれてしまう。この結果、画像の一部が被写界深度外となって良好な結像を得ることができない。
特許文献3の「添付光学系データ1」に示される撮像光学系を同様にして用いた場合には、ΔZrは-0.021、ΔZpは0.031となるから、ΔZr/ΔZpは-0.691となる。やはり最大画角120°未満であるにもかかわらず[数1]の範囲外となり、2ωmaxの光束に対する実像面位置が、ωmaxの光束に対する実像面位置よりも物体側に大きくずれ、良好な結像性能を得ることはできない。
特許文献3の「添付光学系データ2」に示される撮像光学系を用いた場合も同様で、ΔZrは-0.024、ΔZpは0.036となるから、最大画角が120°未満であるにもかかわらずΔZr/ΔZpは-0.666となって[数1]の範囲外である。そのため、2ωmaxの光束に対する実像面位置が、ωmaxの光束に対する実像面位置よりも物体側に大きくずれ、良好な結像性能を得ることはできない。
20 撮像レンズ
L1 第1レンズ
L2 第2レンズ
L3 第3レンズ
L4 第4レンズ
L5 第5レンズ
Claims (6)
- 体内に飲み込まれるカプセルの内部に収容され、前記カプセルの一部を構成する球面状の透明カバーを通して体腔内部の撮像に用いるカプセル型内視鏡用撮像光学系において、
凹状の曲面形状の物体面に正対させて撮像したとき、
-5.0≦ΔZr/ΔZp≦5.0
を満たすことを特徴とするカプセル型内視鏡用撮像光学系。
ただし、前記ΔZrは最大画角2ωmaxの光束に対する実像面位置と半画角ωmaxの光束に対する実像面位置との差を表し、前記ΔZpは前記物体面と2ωmaxの主光線との交点を通り光軸に垂直な平面を仮想物体面としたときの近軸結像位置と、前記物体面とωmaxの主光線との交点を通り光軸に垂直な平面を仮想物体面としたときの近軸結像位置との差を表す。 - 最大画角2ωmaxが135°以上であることを特徴とする請求項1記載のカプセル型内視鏡用撮像光学系。
- 最大画角2ωmaxが120°以上であり、かつ-0.5≦ΔZr/ΔZp≦0.5であることを特徴とする請求項1記載のカプセル型内視鏡用撮像光学系。
- 任意の画角ωに対する像高をY(ω)、任意の画角ωの微小変化量をΔωとするとき、
0.7<(Y(ω+Δω)-Y(ω))/Y(Δω)
を満たすことを特徴とする請求項2または3記載のカプセル型内視鏡用撮像光学系。 - 前記物体面に最も近い位置に物体面に凸面を向けた負レンズ、像面側に最も近い位置に正レンズを有し、前記負レンズの少なくとも像面側の面と、前記正レンズのいずれか一方の面とが非球面であることを特徴とする請求項1~4のいずれか記載のカプセル型内視鏡用撮像光学系。
- 前記負レンズよりも像面側に、複数のレンズで構成され全体として正の正レンズ群を有し、前記正レンズ群の中で、最も物体面側に位置するレンズと最も像面側に位置するレンズとが正レンズであることを特徴とする請求項5記載のカプセル型内視鏡用撮像光学系。
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/257,518 US8542444B2 (en) | 2009-03-24 | 2010-03-24 | Image pickup optical system for capsule endoscope |
EP10756145.8A EP2413176A4 (en) | 2009-03-24 | 2010-03-24 | OPTICAL IMAGE FILING SYSTEM FOR A CAPSULE ENDOSCOPE |
CN201080013445.3A CN102369472B (zh) | 2009-03-24 | 2010-03-24 | 用于胶囊内窥镜的图像拾取光学系统 |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2009-071918 | 2009-03-24 | ||
JP2009071918 | 2009-03-24 | ||
JP2009-074546 | 2009-03-25 | ||
JP2009074546 | 2009-03-25 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2010110349A1 true WO2010110349A1 (ja) | 2010-09-30 |
Family
ID=42781042
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2010/055140 WO2010110349A1 (ja) | 2009-03-24 | 2010-03-24 | カプセル型内視鏡用撮像光学系 |
Country Status (6)
Country | Link |
---|---|
US (1) | US8542444B2 (ja) |
EP (1) | EP2413176A4 (ja) |
JP (1) | JP5412348B2 (ja) |
KR (1) | KR101594957B1 (ja) |
CN (1) | CN102369472B (ja) |
WO (1) | WO2010110349A1 (ja) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN104238090A (zh) * | 2010-11-19 | 2014-12-24 | 大立光电股份有限公司 | 光学摄像透镜组 |
WO2017060949A1 (ja) * | 2015-10-05 | 2017-04-13 | オリンパス株式会社 | 撮像装置及びそれを備えた光学装置 |
Families Citing this family (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5485482B1 (ja) * | 2012-07-03 | 2014-05-07 | オリンパスメディカルシステムズ株式会社 | 内視鏡用対物光学系 |
CN103070660A (zh) * | 2013-01-18 | 2013-05-01 | 浙江大学 | 三维电子内窥镜摄像装置 |
JP5884113B1 (ja) * | 2014-08-07 | 2016-03-15 | ナルックス株式会社 | 撮像光学系 |
CN105445824B (zh) * | 2014-08-20 | 2017-02-22 | 清华大学 | Led光通信接收透镜及led光通信系统 |
JP6356535B2 (ja) * | 2014-08-22 | 2018-07-11 | 京セラ株式会社 | 撮像レンズおよび撮像装置 |
WO2017060950A1 (ja) * | 2015-10-05 | 2017-04-13 | オリンパス株式会社 | 撮像装置及びそれを備えた光学装置 |
JPWO2017064752A1 (ja) * | 2015-10-13 | 2018-08-02 | オリンパス株式会社 | 撮像装置及びそれを備えた光学装置 |
WO2017068726A1 (ja) | 2015-10-23 | 2017-04-27 | オリンパス株式会社 | 撮像装置及びそれを備えた光学装置 |
JP2017134276A (ja) * | 2016-01-28 | 2017-08-03 | オリンパス株式会社 | 撮像装置及びカプセル内視鏡 |
WO2018066641A1 (ja) * | 2016-10-05 | 2018-04-12 | マクセル株式会社 | 撮像レンズ系及び撮像装置 |
JP6800824B2 (ja) * | 2017-09-27 | 2020-12-16 | 富士フイルム株式会社 | 内視鏡用対物光学系および内視鏡 |
WO2019123753A1 (ja) * | 2017-12-21 | 2019-06-27 | オリンパス株式会社 | カプセル内視鏡 |
WO2020053922A1 (ja) * | 2018-09-10 | 2020-03-19 | オリンパス株式会社 | 内視鏡光学系、内視鏡、及び内視鏡システム |
WO2020054012A1 (ja) * | 2018-09-13 | 2020-03-19 | オリンパス株式会社 | 先端部材、内視鏡光学系、内視鏡、及び内視鏡システム |
JP2021012311A (ja) * | 2019-07-08 | 2021-02-04 | 株式会社リコー | 撮像光学系、撮像装置、ステレオカメラ、測距装置及び移動体 |
DE102019008226A1 (de) | 2019-11-26 | 2021-05-27 | Karl Storz Se & Co. Kg | Linsensystem für ein Videoendoskop, Endoskop-Objektiv, Videoendoskop, und Montageverfahren |
CN116830005A (zh) * | 2020-12-14 | 2023-09-29 | 捷普光学德国有限公司 | 环视成像系统 |
JP7213438B1 (ja) | 2022-04-28 | 2023-01-27 | パナソニックIpマネジメント株式会社 | 撮像レンズ系、および、カメラ |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH07181377A (ja) * | 1993-12-24 | 1995-07-21 | Olympus Optical Co Ltd | 内視鏡用対物レンズ |
JP2006243689A (ja) * | 2005-02-03 | 2006-09-14 | Olympus Corp | 光学系 |
JP2008309859A (ja) * | 2007-06-12 | 2008-12-25 | Olympus Corp | 光学系及びそれを用いた内視鏡 |
JP2009276371A (ja) * | 2008-05-12 | 2009-11-26 | Olympus Medical Systems Corp | 内視鏡用画像装置 |
Family Cites Families (22)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2628627B2 (ja) * | 1985-01-11 | 1997-07-09 | オリンパス光学工業株式会社 | 内視鏡用非球面対物レンズ |
JPH02277015A (ja) * | 1989-04-19 | 1990-11-13 | Olympus Optical Co Ltd | 内視鏡対物光学系 |
JP2566487B2 (ja) | 1990-09-18 | 1996-12-25 | 新日本製鐵株式会社 | 複数のボイラーおよび発電機の蒸気圧力制御方法 |
JPH04128504A (ja) | 1990-09-19 | 1992-04-30 | Hitachi Ltd | 速度信号入力回路 |
JPH05307139A (ja) * | 1992-04-28 | 1993-11-19 | Olympus Optical Co Ltd | 内視鏡対物レンズ |
JP3895618B2 (ja) * | 2002-03-08 | 2007-03-22 | オリンパス株式会社 | カプセル型内視鏡 |
JP2005074031A (ja) * | 2003-09-01 | 2005-03-24 | Pentax Corp | カプセル内視鏡 |
JP5178991B2 (ja) | 2004-08-27 | 2013-04-10 | オリンパス株式会社 | カプセル型内視鏡 |
JP4128505B2 (ja) | 2003-09-05 | 2008-07-30 | オリンパス株式会社 | カプセル型内視鏡 |
JP4128504B2 (ja) * | 2003-09-05 | 2008-07-30 | オリンパス株式会社 | カプセル型内視鏡 |
US7245443B2 (en) | 2004-08-17 | 2007-07-17 | Olympus Corporation | Panoramic attachment optical system, and panoramic optical system |
JP4516475B2 (ja) * | 2005-04-27 | 2010-08-04 | オリンパスメディカルシステムズ株式会社 | 略球形状の観察窓を有する内視鏡用撮像光学系 |
JP4611115B2 (ja) * | 2005-05-26 | 2011-01-12 | オリンパス株式会社 | 光学系 |
JP4914600B2 (ja) * | 2005-11-10 | 2012-04-11 | オリンパスメディカルシステムズ株式会社 | 生体内画像取得装置、受信装置および生体内情報取得システム |
JP4674906B2 (ja) * | 2006-07-03 | 2011-04-20 | オリンパス株式会社 | 光学系 |
JP5214161B2 (ja) * | 2006-07-10 | 2013-06-19 | オリンパス株式会社 | 透過光学素子及びそれを用いた光学系 |
JP4308233B2 (ja) * | 2006-09-01 | 2009-08-05 | オリンパスメディカルシステムズ株式会社 | 内視鏡用撮像モジュール |
CN100464207C (zh) * | 2007-04-11 | 2009-02-25 | 王华林 | 上消化道电子内窥镜物镜 |
CN101688970B (zh) * | 2007-07-09 | 2013-07-03 | 奥林巴斯株式会社 | 光学系统及应用该光学系统的内窥镜 |
CN100582855C (zh) * | 2007-08-23 | 2010-01-20 | 鸿富锦精密工业(深圳)有限公司 | 内视镜头及内视镜装置 |
WO2011027622A1 (ja) * | 2009-09-01 | 2011-03-10 | オリンパスメディカルシステムズ株式会社 | 対物光学系 |
US20110169931A1 (en) * | 2010-01-12 | 2011-07-14 | Amit Pascal | In-vivo imaging device with double field of view and method for use |
-
2010
- 2010-03-24 EP EP10756145.8A patent/EP2413176A4/en not_active Withdrawn
- 2010-03-24 JP JP2010068737A patent/JP5412348B2/ja active Active
- 2010-03-24 WO PCT/JP2010/055140 patent/WO2010110349A1/ja active Application Filing
- 2010-03-24 CN CN201080013445.3A patent/CN102369472B/zh active Active
- 2010-03-24 KR KR1020117021965A patent/KR101594957B1/ko not_active IP Right Cessation
- 2010-03-24 US US13/257,518 patent/US8542444B2/en active Active
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH07181377A (ja) * | 1993-12-24 | 1995-07-21 | Olympus Optical Co Ltd | 内視鏡用対物レンズ |
JP2006243689A (ja) * | 2005-02-03 | 2006-09-14 | Olympus Corp | 光学系 |
JP2008309859A (ja) * | 2007-06-12 | 2008-12-25 | Olympus Corp | 光学系及びそれを用いた内視鏡 |
JP2009276371A (ja) * | 2008-05-12 | 2009-11-26 | Olympus Medical Systems Corp | 内視鏡用画像装置 |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN104238090A (zh) * | 2010-11-19 | 2014-12-24 | 大立光电股份有限公司 | 光学摄像透镜组 |
WO2017060949A1 (ja) * | 2015-10-05 | 2017-04-13 | オリンパス株式会社 | 撮像装置及びそれを備えた光学装置 |
Also Published As
Publication number | Publication date |
---|---|
KR20110137780A (ko) | 2011-12-23 |
CN102369472B (zh) | 2014-06-04 |
EP2413176A4 (en) | 2014-07-30 |
US8542444B2 (en) | 2013-09-24 |
KR101594957B1 (ko) | 2016-02-17 |
JP5412348B2 (ja) | 2014-02-12 |
JP2010246906A (ja) | 2010-11-04 |
CN102369472A (zh) | 2012-03-07 |
US20120016199A1 (en) | 2012-01-19 |
EP2413176A1 (en) | 2012-02-01 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5412348B2 (ja) | カプセル型内視鏡用撮像光学系 | |
JP5441465B2 (ja) | カプセル型内視鏡 | |
US7505802B2 (en) | Capsule endoscope | |
JP5324321B2 (ja) | 内視鏡用対物レンズおよび内視鏡 | |
US7796342B2 (en) | Imaging lens system and capsule endoscope | |
US10948708B2 (en) | Objective optical system for endoscope and endoscope | |
JPWO2017146021A1 (ja) | 内視鏡用変倍光学系、内視鏡及び内視鏡システム | |
JP2009136387A (ja) | 撮像レンズ及びカプセル内視鏡 | |
JPWO2017068726A1 (ja) | 撮像装置及びそれを備えた光学装置 | |
JP2018180422A (ja) | 撮像装置 | |
JP2009300797A (ja) | 撮像レンズ及びカプセル型内視鏡 | |
JP2009136385A (ja) | 撮像レンズ及びカプセル内視鏡 | |
JP6873741B2 (ja) | 撮像装置 | |
CN112748556A (zh) | 一种内窥镜光学系统 | |
JP2018055059A (ja) | 撮像装置 | |
JP2009136386A (ja) | 撮像レンズ及びカプセル内視鏡 | |
CN109983383B (zh) | 内窥镜物镜光学系统 | |
JP2009300796A (ja) | 撮像レンズ及びカプセル型内視鏡 | |
CN111095068B (zh) | 内窥镜用物镜单元与内窥镜 | |
US11933961B2 (en) | Stereoscopic vision endoscope objective optical system and endoscope using the same | |
WO2020053922A1 (ja) | 内視鏡光学系、内視鏡、及び内視鏡システム | |
JP2009297308A (ja) | 撮像レンズ及びカプセル型内視鏡 | |
JP2009297307A (ja) | 撮像レンズ及びカプセル型内視鏡 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 201080013445.3 Country of ref document: CN |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 10756145 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2010756145 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 13257518 Country of ref document: US |
|
ENP | Entry into the national phase |
Ref document number: 20117021965 Country of ref document: KR Kind code of ref document: A |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 6954/CHENP/2011 Country of ref document: IN |