CA1058436A - Elongated rod lens optical system - Google Patents
Elongated rod lens optical systemInfo
- Publication number
- CA1058436A CA1058436A CA251,189A CA251189A CA1058436A CA 1058436 A CA1058436 A CA 1058436A CA 251189 A CA251189 A CA 251189A CA 1058436 A CA1058436 A CA 1058436A
- Authority
- CA
- Canada
- Prior art keywords
- rod lenses
- optical system
- lens
- rod
- fluid
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- 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
- G02B23/2446—Optical details of the image relay
-
- 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
- A61B1/002—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 having rod-lens arrangements
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B3/00—Simple or compound lenses
- G02B3/12—Fluid-filled or evacuated lenses
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Optics & Photonics (AREA)
- Surgery (AREA)
- General Physics & Mathematics (AREA)
- Biomedical Technology (AREA)
- General Health & Medical Sciences (AREA)
- Pathology (AREA)
- Engineering & Computer Science (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- Heart & Thoracic Surgery (AREA)
- Medical Informatics (AREA)
- Molecular Biology (AREA)
- Animal Behavior & Ethology (AREA)
- Radiology & Medical Imaging (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Biophysics (AREA)
- Astronomy & Astrophysics (AREA)
- Lenses (AREA)
- Instruments For Viewing The Inside Of Hollow Bodies (AREA)
- Endoscopes (AREA)
Abstract
Abstract of the Disclosure An optical system for conveying an optical image having two first biconvex rod lenses arranged end to end on a common optical axis in spaced relationship, and between said first rod lenses but not in contact with them a pair of second rod lenses also arranged end to end on the same axis, the adjacent ends of the second rod lenses being concave and de-fining a biconvex cavity which can contain a fluid whereby a fluid lens is formed, the system being substantially sym-metrical about a median plane through a biconvex cavity and the modulus of the reciprocal of the radius of curvature of the fluid lens being less than or equal to the modulus of the difference between the reciprocal of the radius of curvature of the convex surfaces of the first rod lenses adjacent to the second rod lenses and the reciprocal of the radius of curvature of the convex surfaces of the second rod lenses adjacent to the first rod lenses.
Description
~(~S843f~
This invention relates to optical systems and relates particularly to optical systems for relaying an optical image along a long, relatively narrow tube-like opticaliinstrument, such as an endoscope.
When an optical image is relayed by a series of posi tive lenses, errors of field curvature and astigmatism may occur.
One method of relaying an optical image along a tube is disclosed in UK Patent No. 954,629 in which at least two rod lenses are used to convey an image. Such a method can be used in an instru-ment to view a useful field withaacceptably small astigmatismand image curvature, and is particularly described in the speci-fication with referencs to a cystoscope. If this system is used for a laparoscope, in which wider angles of view and higher aper-tures are employed the aberrations may not be corrected adequately, especially if a photographic record is required.
According to the invention, an optical system for conveying an optical image comprises two first biconvex rod lenses arranged end to end on a common optical axis in spaced relation-ship and between said first rod lenses but not in contact with them a pair of second rod lenses also arranged end to end on the same axis, the adjacent ends of the second rod lenses being concave and defining a biconvex cavity which can contain a 1uid whereby a fluid lens is formed, the system being substantially ; symmetrical about a median plane through the biconvex cavity and the modulus of the reciprocal of the radius of curvature of each surface of the fluid lens being less than or equal to the modulus of the difference between the reciprocal of the radius of curva ;-ture of each of the convex surfaces of the first rod lenses adjace~t~to the second rod lenses and the reciprocal of the radius of curvature of each of the convex surfaces of the second rod lenses adjacent to the first rod lemses.
~1~5~3436 Preferably the axial length of each of the second pair of rod lenses is greater than 0.8 times the numerical value of the radius of curvature of each surface of the fluid lens.
To provide further correction of any optical errors, and more particularly the chromatic aberration, meniscus lens elements may be arranged one in each space between the first and second rod lenses and each meniscus lens element may be attached either to an end of a first rod lens or to an end of a second lens, the meniscus lens elements haviny a higher refractive index than the lenses to which they are attached. The refractive index of the second rod lenses should be not greater than 1.55.
The fluid comprising the fluid lens may, for example, be air or water and the fluid may also fill any spaces axially between the first and second rod lenses.
The curvature of the fluid lens in relation to the curvature of the adjacent convex surfaces of the first and second rod lenses can be expressed in mathematical terms as follows:
/ C5 / -~~~~~~ / C3 - C4 /
C3 being the curvature ( = 1 ) of the convex radius surface of the first rod lens adjacent to the second rod lens, C4 being curvature of the convex surface of the second rod lens adjacent the first rod lens and C5 being the curvature of each surface of the fluid lens.
The customary cartesian convention for the sign of curvature of a surface is that the sign is positive if the centre of curvature is to the right of the surface and negative if the centre of curvature is to the left of the surface.
One or more systems according to the invention may be used to relay an image along a tube-like optical instrument such as an endoscope.
.~ . , -. ~ . .
~058a~36 The invention ~ill ngw be described by way of example with reference to the drawings filed herewith in which:
Figure 1 illustrates in section one form of optical system according to the invention.
Figure 2 illustrates in section an alternative form of optical system~ and figure 3 illustrates diagrammatically use of the system shown in Figure 1 in an endoscope.
In figure 1, two first biconvex rod lenses 10, 11 each have attached at one end a negative meniscus element 12, 13 respectively. Between lenses 10, 11 are two second rod lenses 14, 15 the adjacent faces of which 16, 17 are partially concave and which define a biconvex air lens 18. The meniscus elements 12, 13 are separate axially from the second rod lenses, 14, 15 by air gaps 19, 20.
The full specification of the optical system shown in Figure 1 is given in Table I below:
' 1~5843~i Table I
. . .
Radius Axlal thick- Reiractive Dlspersion mm ness mm index .... .~ .. _ _ _ 12.7~2 Rod lens 10 28,179 1.5168 64~17 and meniscus - 5.36 element 12 1.248 1.68893 31.18 - 9.528 . _ _ _ _ .. __ ,. .. __ Air gap 19 0.312 ,_ 0 Rod lens 145.870 4.075 4.327 1.5168 64.17 ~ __._ - _ Air lens 18 0.512 1 0 . , _ , ~... , ___ Rod lens 15- 4.075 - 5.~70 4.327 1.5168 64.17 ~ __ _ _ . _ Air Gap 20 0.312 1 0 _ 9.5-2~-- _ _ __ Meniscus 1.248 1~68893 31.18 element 135.369 and rod lens 1] 28.179 1.5168 64.17 -12.752 _ _ _ _ _ _ 105~436 In Figure 2, two first rod lenses 22, 23 are arranged with two second rod lenses 24, 25 between them, the lenses 24, 25 each havin~ a convex surface, which surfaces define a bi-convex air lens 26. To the lenses 24, 25 are attached meniscus elements 27, 28 respectively.
In Figure 3 an endoscope 29 comprises a tube contain-ing at one end a negative lens 31 and biconvex lenses 32, 33 forming an objective lens system. The endoscope contains typical-ly five of the optical systems shown in Figure 1 or Figure 2 although only two are shown ir detail, as references 10 to 15, and also contains eyepiece lenses 34, 35. The lenses are spaced in the tube by annular spacers (not shown). Such an endoscope may have an angle of field equal to 70.
In general an optical system according to the invention is suitable for use when an image is to be relayed along a tube of diameter much less than its length. In a typical case the diameter would be less than lOmm, and the length would be substan-tially greater than the diameter, for example, by a factor of ten or more. The system is applicable to any endoscopes, such as, for example, cystoscopes and bronchoscopes.
. -~
This invention relates to optical systems and relates particularly to optical systems for relaying an optical image along a long, relatively narrow tube-like opticaliinstrument, such as an endoscope.
When an optical image is relayed by a series of posi tive lenses, errors of field curvature and astigmatism may occur.
One method of relaying an optical image along a tube is disclosed in UK Patent No. 954,629 in which at least two rod lenses are used to convey an image. Such a method can be used in an instru-ment to view a useful field withaacceptably small astigmatismand image curvature, and is particularly described in the speci-fication with referencs to a cystoscope. If this system is used for a laparoscope, in which wider angles of view and higher aper-tures are employed the aberrations may not be corrected adequately, especially if a photographic record is required.
According to the invention, an optical system for conveying an optical image comprises two first biconvex rod lenses arranged end to end on a common optical axis in spaced relation-ship and between said first rod lenses but not in contact with them a pair of second rod lenses also arranged end to end on the same axis, the adjacent ends of the second rod lenses being concave and defining a biconvex cavity which can contain a 1uid whereby a fluid lens is formed, the system being substantially ; symmetrical about a median plane through the biconvex cavity and the modulus of the reciprocal of the radius of curvature of each surface of the fluid lens being less than or equal to the modulus of the difference between the reciprocal of the radius of curva ;-ture of each of the convex surfaces of the first rod lenses adjace~t~to the second rod lenses and the reciprocal of the radius of curvature of each of the convex surfaces of the second rod lenses adjacent to the first rod lemses.
~1~5~3436 Preferably the axial length of each of the second pair of rod lenses is greater than 0.8 times the numerical value of the radius of curvature of each surface of the fluid lens.
To provide further correction of any optical errors, and more particularly the chromatic aberration, meniscus lens elements may be arranged one in each space between the first and second rod lenses and each meniscus lens element may be attached either to an end of a first rod lens or to an end of a second lens, the meniscus lens elements haviny a higher refractive index than the lenses to which they are attached. The refractive index of the second rod lenses should be not greater than 1.55.
The fluid comprising the fluid lens may, for example, be air or water and the fluid may also fill any spaces axially between the first and second rod lenses.
The curvature of the fluid lens in relation to the curvature of the adjacent convex surfaces of the first and second rod lenses can be expressed in mathematical terms as follows:
/ C5 / -~~~~~~ / C3 - C4 /
C3 being the curvature ( = 1 ) of the convex radius surface of the first rod lens adjacent to the second rod lens, C4 being curvature of the convex surface of the second rod lens adjacent the first rod lens and C5 being the curvature of each surface of the fluid lens.
The customary cartesian convention for the sign of curvature of a surface is that the sign is positive if the centre of curvature is to the right of the surface and negative if the centre of curvature is to the left of the surface.
One or more systems according to the invention may be used to relay an image along a tube-like optical instrument such as an endoscope.
.~ . , -. ~ . .
~058a~36 The invention ~ill ngw be described by way of example with reference to the drawings filed herewith in which:
Figure 1 illustrates in section one form of optical system according to the invention.
Figure 2 illustrates in section an alternative form of optical system~ and figure 3 illustrates diagrammatically use of the system shown in Figure 1 in an endoscope.
In figure 1, two first biconvex rod lenses 10, 11 each have attached at one end a negative meniscus element 12, 13 respectively. Between lenses 10, 11 are two second rod lenses 14, 15 the adjacent faces of which 16, 17 are partially concave and which define a biconvex air lens 18. The meniscus elements 12, 13 are separate axially from the second rod lenses, 14, 15 by air gaps 19, 20.
The full specification of the optical system shown in Figure 1 is given in Table I below:
' 1~5843~i Table I
. . .
Radius Axlal thick- Reiractive Dlspersion mm ness mm index .... .~ .. _ _ _ 12.7~2 Rod lens 10 28,179 1.5168 64~17 and meniscus - 5.36 element 12 1.248 1.68893 31.18 - 9.528 . _ _ _ _ .. __ ,. .. __ Air gap 19 0.312 ,_ 0 Rod lens 145.870 4.075 4.327 1.5168 64.17 ~ __._ - _ Air lens 18 0.512 1 0 . , _ , ~... , ___ Rod lens 15- 4.075 - 5.~70 4.327 1.5168 64.17 ~ __ _ _ . _ Air Gap 20 0.312 1 0 _ 9.5-2~-- _ _ __ Meniscus 1.248 1~68893 31.18 element 135.369 and rod lens 1] 28.179 1.5168 64.17 -12.752 _ _ _ _ _ _ 105~436 In Figure 2, two first rod lenses 22, 23 are arranged with two second rod lenses 24, 25 between them, the lenses 24, 25 each havin~ a convex surface, which surfaces define a bi-convex air lens 26. To the lenses 24, 25 are attached meniscus elements 27, 28 respectively.
In Figure 3 an endoscope 29 comprises a tube contain-ing at one end a negative lens 31 and biconvex lenses 32, 33 forming an objective lens system. The endoscope contains typical-ly five of the optical systems shown in Figure 1 or Figure 2 although only two are shown ir detail, as references 10 to 15, and also contains eyepiece lenses 34, 35. The lenses are spaced in the tube by annular spacers (not shown). Such an endoscope may have an angle of field equal to 70.
In general an optical system according to the invention is suitable for use when an image is to be relayed along a tube of diameter much less than its length. In a typical case the diameter would be less than lOmm, and the length would be substan-tially greater than the diameter, for example, by a factor of ten or more. The system is applicable to any endoscopes, such as, for example, cystoscopes and bronchoscopes.
. -~
Claims (10)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An optical system for conveying an optical image having two first biconvex rod lenses arranged end to end on a common optical axis in spaced relationship, and between said first rod lenses but not in contact with them a pair of second rod lenses also arranged end to end on the same axis, the adjacent ends of the second rod lenses being concave and defining a biconvex cavity which contains a fluid whereby a fluid lens is formed, the system being substantially symmet-rical about a median plane through the biconvex cavity and the modulus of the reciprocal of the radius of curvature of each surface of the fluid lens being less than or equal to the modulus of the difference between the reciprocal of the radius of curvature of each of the convex surfaces of the first rod lenses adjacent to the second rod lenses and the reciprocal of the radius of curvature of each of the convex surfaces of the second rod lenses adjacent to the first rod lenses.
2. An optical system according to claim 1 in which the axial length of each of the pair of second rod lenses is greater than 0,8 times the numerical value of the radius of curvature of each surface of the fluid lens.
3. An optical system according to claim 1 in which meniscus lens elements are arranged one in each space between first and second rod lenses.
4. An optical system according to claim 3 in which at least one of said meniscus lens elements is attached to an end of one of said rod lenses, the refractive index of the meniscus lens element being higher than that of the rod lens to which it is attached.
5. An optical system according to claim 1 in which the refractive index of the second rod lenses is not greater than 1.55.
6. An optical system according to claim 1 in which the fluid of the fluid lens is air.
7. An optical system according to claim 1 in which the fluid of the fluid lens is water.
8. An optical system according to claim 1 in which any spaces axially between the first and second rod lens is filled with air.
9. An optical system according to claim 7 in which any spaces axially between the first and second rod lenses are filled with water.
10. An optical system, according to claim 1, for use in an endoscope.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1807475A GB1534541A (en) | 1975-04-30 | 1975-04-30 | Optical systems |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1058436A true CA1058436A (en) | 1979-07-17 |
Family
ID=10106216
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA251,189A Expired CA1058436A (en) | 1975-04-30 | 1976-04-27 | Elongated rod lens optical system |
Country Status (9)
| Country | Link |
|---|---|
| JP (1) | JPS524245A (en) |
| AU (1) | AU497311B2 (en) |
| BR (1) | BR7602650A (en) |
| CA (1) | CA1058436A (en) |
| CH (1) | CH607060A5 (en) |
| DE (1) | DE2619393C2 (en) |
| FR (1) | FR2309886A1 (en) |
| GB (1) | GB1534541A (en) |
| IT (1) | IT1059435B (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2489135A1 (en) * | 1980-09-03 | 1982-03-05 | Metallisations Traitements Opt | VARIABLE FIELD ENDOSCOPIC SYSTEM FOR DISTAL OR NON-DISTAL OBSERVATION |
| JP2580103B2 (en) * | 1984-07-06 | 1997-02-12 | オリンパス光学工業株式会社 | Image transmission optical system |
| JPH0762736B2 (en) * | 1984-09-25 | 1995-07-05 | オリンパス光学工業株式会社 | Image transmission optics |
| JPS61184513A (en) * | 1984-10-02 | 1986-08-18 | Olympus Optical Co Ltd | Image transmitting optical system |
| JPH0823625B2 (en) * | 1985-07-25 | 1996-03-06 | オリンパス光学工業株式会社 | Image transmission optical system using inhomogeneous lens |
| US5206759A (en) * | 1989-04-14 | 1993-04-27 | Olympus Optical Co., Ltd. | Image relaying optical system |
| US5142410A (en) * | 1989-04-14 | 1992-08-25 | Olympus Optical Co., Ltd. | Image relaying optical system |
| US5204162A (en) * | 1991-10-03 | 1993-04-20 | Corning Incorporated | Non-spherical bodies |
| JPH0694989A (en) * | 1992-08-22 | 1994-04-08 | Dr Canzek Endoscopie Ag | Optical relay lens system |
| JPH09113796A (en) * | 1995-10-20 | 1997-05-02 | Olympus Optical Co Ltd | Hard mirror optical system |
| DE10136117A1 (en) * | 2001-07-26 | 2003-04-03 | Storz Karl Gmbh & Co Kg | Image transmission system consisting of three rod lenses for rigid endoscopes |
| DE102005027880A1 (en) | 2005-06-09 | 2006-12-21 | Karl Storz Gmbh & Co. Kg | rod lens |
| DE102016115738A1 (en) | 2016-08-24 | 2018-03-01 | Karl Storz Gmbh & Co. Kg | Endoscope and relay lens system for transmitting an image |
| EP3173846B1 (en) | 2015-11-05 | 2023-10-04 | Karl Storz SE & Co. KG | Optical relay system |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1260786A (en) * | 1960-04-01 | 1961-05-12 | Commissariat Energie Atomique | Endoscopic scope |
| DE2333280C2 (en) * | 1973-06-29 | 1982-05-06 | Günther Dr. 8022 Grünwald Nath | Flexible light guide |
-
1975
- 1975-04-30 GB GB1807475A patent/GB1534541A/en not_active Expired
-
1976
- 1976-04-27 CA CA251,189A patent/CA1058436A/en not_active Expired
- 1976-04-29 IT IT4926176A patent/IT1059435B/en active
- 1976-04-29 BR BR7602650A patent/BR7602650A/en unknown
- 1976-04-30 FR FR7612961A patent/FR2309886A1/en active Granted
- 1976-04-30 JP JP51050732A patent/JPS524245A/en active Pending
- 1976-04-30 DE DE19762619393 patent/DE2619393C2/en not_active Expired
- 1976-04-30 AU AU13554/76A patent/AU497311B2/en not_active Expired
- 1976-04-30 CH CH546476A patent/CH607060A5/xx not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| AU1355476A (en) | 1977-11-03 |
| GB1534541A (en) | 1978-12-06 |
| DE2619393C2 (en) | 1985-03-07 |
| CH607060A5 (en) | 1978-11-30 |
| JPS524245A (en) | 1977-01-13 |
| AU497311B2 (en) | 1978-12-07 |
| BR7602650A (en) | 1976-11-23 |
| DE2619393A1 (en) | 1976-11-11 |
| IT1059435B (en) | 1982-05-31 |
| FR2309886A1 (en) | 1976-11-26 |
| FR2309886B1 (en) | 1982-05-14 |
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