CA2233211A1 - Dark field illuminator ringlight adaptor - Google Patents
Dark field illuminator ringlight adaptor Download PDFInfo
- Publication number
- CA2233211A1 CA2233211A1 CA002233211A CA2233211A CA2233211A1 CA 2233211 A1 CA2233211 A1 CA 2233211A1 CA 002233211 A CA002233211 A CA 002233211A CA 2233211 A CA2233211 A CA 2233211A CA 2233211 A1 CA2233211 A1 CA 2233211A1
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- Prior art keywords
- light
- ringlight
- annular
- aperture
- reflective surface
- 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.)
- Abandoned
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Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B21/00—Microscopes
- G02B21/06—Means for illuminating specimens
- G02B21/08—Condensers
- G02B21/10—Condensers affording dark-field illumination
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B21/00—Microscopes
- G02B21/06—Means for illuminating specimens
- G02B21/08—Condensers
- G02B21/082—Condensers for incident illumination only
- G02B21/084—Condensers for incident illumination only having annular illumination around the objective
Abstract
A system enabling conversion of a conventional ringlight for differential illumination such as dark field or Rheinberg illumination is disclosed. The system comprises a ringlight having an annular light emitting portion and a hood that fits over the ringlight. The hood has an aperture and an annular reflective surface, disposed opposite the light emitting portion, that reflects the light from the ringlight through the aperture. An angle of the annular reflective surface is selected relative to a direction of light from the ringlight to form a cone of light exiting the aperture. To ensure good contrast, a light baffle in the form of a sleeve, inserted into the ringlight, may be incorporated to prevent stray light from the ringlight from directly exiting through the aperture. The differential illumination produced by the invention is applicable to machine vision applications, but also microscopy, gemology, and serology, for example.
Description
WO 97/15~56 PCTAJS96/17195 ~ARK FIELD ILLUMINATOR RINGLIGHT ADAPTOR
Backqround of the Invention Many diverse methods of optical imaging and assisted viewing reguire some type of specimen illumination. Microscopes magnify light from only a small area with a con~or;tant reduction in light intensity. This necessitates intense illumination of the specimen in order to provide adequate light levels for viewing. Machine vision applications often achieve better performance with intense illumination, which provides better resolution of the workpiece's or specimen's details. Identifying workpiece edges and surface features allows the position and orientation to be determined automatically.
-Generally the lighting can originate from in front o~ or behind the specimen. Microscopes commonly use backlighting with a light source below a specimen stage that directs light upward through a microscope slide held on the stage to its first optical element, or the microscope objective. This lighting configuration istypically used for a transparent or translucent specimen since the light must pass through the specimen to be captured by the microscope. Light sourced ~rom above the specimen is typically used with opaque specimens.
When lighting from above the specimen, a problem stems from the fact that a single point light source can not be located in line with the microscope~s optical axis without obstructing its view or a complex optical arrangement. The specimen is thus usually W O 97/15856 PCT~US96/17195 illuminated from light off the axis, but this can create shadows. The solution to this dilemma is a device termed a ringlight. This device i5 typically torroidal in shape to fit around the barrel of the microscope or similar optical apparatus. The barrel and ringlight are arranged so that the barrel i8 coextensive with the ringlight's axis. The ringlight emits light in a 3~0 degree circle in the general direction of its axis, but angling inward slightly.
This forms a cone of light having a vertex located on the axis. When used as a microscope light, for example, the specimen is illuminated evenly from all sides without shadows being visible through the microscope.
There are a number of variations on the backlighting theme. One such variation is a form of differential illumination termed dark ~ield illumination. Many specimens exhibit little or no contrast when viewed with ordinary backlighting because they are colorless and transparent. Chemical stA;n;ng is the typical solution in this situation, but in some cases it may be undesirable. In dark field illumination, the specimen is illuminated with a hollow cone of light aligned along the optical axis of the microscope and originating from below the specimen. The microscope objective is located within the dark base of the hollow light cone. Consequently, without a specimen, there is no illumination in the microscope.
A specimen placed on the stage, however, tends to diffract, reflect, and refract light of the cone, and this scattered light can then enter the objective.
When observed through the microscope, live bacteria, for example, are visible, their edges and internal structures being outlined by redirected light, which is collected by the microscope optics. Rheinberg dif~erential illumination is similar except that the field is given a desired color with diffuse lighting.
Summarv of the Invention The present invention concerns a differential ~ 5 illumination system that uses a ringlight or similar source of electromagnetic radiation. Light from the ringlight is redirected to form a cone of light projecting upward and away from the system. This enables dark field or Rheinberg illumination, for example. As a result, if desired the invention may be used to retrofit conventional ringlights, adapted for general purpose illumination, for these specialized techniques.
In general, according to one aspect, the invention _ 15 ~eatures an illumination system. The system comprises a ringlight having an annular light emitting portion and a hood that fits over the ringlight. The hood has an aperture and an annular reflective surface, disposed opposite the light emitting portion, that reflects the light from the ringlight through the aperture.
In specific embodiments, the ringlight receives light via a fiber optic bundle and the annular light emitting portion comprises a ring of these fibers from the bundle.
When adapted for di~ferential illumination such as dark field or Rheinberg illumination, an angle of the annular reflective sur~ace is selected relative to a direction of light from the ringlight to form a cone of light exiting the aperture. To ensure good contrast, a light baffle may be incorporated to prevent stray light from the ringlight from directly exitlng through the aperture. This baf~i~le is pre~erably ~ormed i~rom a sleeve inserted into a center bore o:E the ringlight.
If a di:E~use cone is desired, a dif~usion screen may be also added.
Further, a i~ield illumination light source may be added to emit a di~used light to enable the Rheinberg di~i~erential illumination.
In general, according to another aspect, the invention may also be characterized as a system i~or converting a ringlight, which is adapted :Eor conventional illumination, to provide di~:Eerential illumination. Such a system would comprise the hood that has been adapted to i~it over the ringlight to properly redirect the output :Erom it.
In general, according to another aspect, the invention may also be characterized as a method ~or converting a ringlight i~or di~erential illumination in a viewing device, such as a microscope. This method comprises blocking light ~rom the ringlight from being transmitted directly into the viewing device. The light i~rom the ringlight, however, is re~lected to ~orm a hollow cone o~ light. An objective of the viewing device is then placed within the hollow cone oE light.
This enables dark f~ield viewing since only structures within a specimen will direct light to the viewing device.
The above and other :Eeatures o~ the invention including various novel details o:E construction and combinations oi~ parts, and other advantages, will now be more particularly described with re~erence to the accompanying drawings and pointed out in the claims.
It will be understood that the particular method and device embodying the invention are shown by way o~
illustration and not as a limitation o~ the invention.
The principles and ~eatures o~ this invention may be employed in various and numerous embodiments without departing ~rom the scope o~ the in~ention.
~rie~ PescriPtion of the Drawinqs In the accompanying drawings, re~erence characters re~er to the same parts throughout the di~erent views.
The drawings are not necessarily to scale; emphasis has instead been placed upon illustrating the principles o~
the invention. 0~ the drawings:
Fig. 1 illustrates the prior art use o~ a ringlight as a light source positioned above the specimen;
- Fig. 2 is a perspective and exploded view o~ a di~erential illumination system o~ the present invention con~igured ~or dark ~ield illumination and showing a partial cut-away in the ringlight adaptor-re~1ector hood;
Fig. 3 is cross-sectional view o~ the inventive dark ~ield illuminator;
Figs. 4A, 4B, and 4C are partial cross-sectional views showing the illuminator with a modification ~or providing adjustment of the angle o~ the light cone;
Fig. 5 shows a modi~ication o~ the inventive illuminator ~or Rheinberg di~erential color illumination; and Fig. 6 is a perspective exploded view o~ another embodiment o~ the inventive system that has a removable cover.
Descri~tion of Pre:Eerred Embodiments Turning now to the drawings, Fig. 1 illustrates the typical application of a conventional ringlight as a microscope illuminator. The ringlight 110 is attached to the barrel o~ a microscope 50. It generates a cone of light 150 which is directed downward to the stage 310 to illuminate a specimen on slide 314. The ringlight itself typically receives light via a fiber optic cable 116 from a source 318.
Fig. 2 shows a dif~erential illumination system 100 based on the conventional ringlight 110 that has been constructed according to the principles of the present invention. The system 100 comprises a re~lector hood 200 that ~its over the ringlight llo.
An inner sleeve 120 is press fit into the center - aperture 112 of the ringlight 110. Finally, an end cap 130 covers a center cavity 132 defined by the inner surface o~ the sleeve 120 to ~orm a dark field stop at the bottom o~ the illuminator 100. This prevents light seepage into the center cavity 132.
In operation, the system 100 is located under a microscope stage 310 to illuminate a specimen 312 held on slide 314. The microscope objective 316 captures light for viewing by a user or imaged on a charge coupled device, for example.
The hood 200 is preferably constructed from machined aluminum and has a non-re~lecting, light absorbent, finish on most o~ its outer surfaces. Black anodization is one possible technique ~or achieving these sur~ace characteristics. The hood 200 is generally cylindrical with a bore 202 extending axially through the hood. The proximal end 204 o~ the bore is CA 022332ll l998-04-24 frustro-conical, a terminal end of which is a light emitting aperture 206. The frustro-conical portion of the bore yields an inner chamfered surface 208 that is polished for maximum light reflectance. The light reflecting surface 208 is angled at approximately 45 degrees, preferably 42 degrees with respect to the central axis 102. The distal end 210 of the bore is essentially cylindrical and is sized to receive the ringlight 110.
The ringlight 110 is installed into the distal end 210 o~ the bore. In one embodiment it is held in place by a bolt 212 threaded into the hood 200 and engaging a dimple 113 in the outer suri~ace of ringlight 110.
Indexing may be provided by forming multiple dimples 114 axially along the outer surface of the ringlight - 110 to enable height adjustment of the ringlight 110 within the hood 200.
The ringlight 110 is preferably a fiber optic type light system such as the Dolan-Jenner ringlight Model No. A3739P. A fiber optic bundle 116 connects to receive light from a light source 318. The bundle 116 may be glass, plastic or quartz fibers, to list a ~ew alternatives. At the point of connection a light ~ilter 320 can be added to adapt the color oE the light for Rheinberg dii~ferential color illumination, for example. Light from the source 318 is coupled into the bundle 116 and transmitted to the ringlight 110.
There, the individual fibers 118 are separated and dispersed evenly around the circumference of the ringlight. The terminal end 119 of the fibers 118 are aligned generally axially but angled lnward slightly, .
WO 97tl5856 PCTAUS96/17195 18 degrees in the particular ringlight illustrated, to generate a cone of light 150 having an acute angle vertex.
other types of ringlights are compatible with the invention. For example, using a circle of light emitting diodes on the housing of the ringlight might be preferred in applications in which it is dif~icult to accommodate the thick fiber optic bundle 116.
As best shown in Fig. 3, the light 150 emitted ~rom the ringlight is re~lected o~ of the light re~lective surface 208 o~ the hood 200. The light then travels out through the light emitting aperture 206.
The light exiting the aperture is substantially 25 degrees from horizontal. The result is a hollow light _ 15 cone 152 projecting upward ~rom the aperture 206. The trajectory of the light is such that it will not enter the light collection optics 316 of the imaging device, the microscope objective. The specimen 312 placed on the slide 314 will tend to reflect, refract, and di~ract light toward the microscope objective 116, however.
In some applications, a more di~use light cone may be desirable. A diffusion screen 168 may be added in these cases. The pre~erred location is across the aperture 206.
The inner sleeve 120 functions as a light ba~fle.
Good contrast in dark ~ield illumination requires keeping light from the illuminator 100 only in the hollow cone 152. The ~ibers, however, tend to emit a portion o~ the light of~ o~ their central axes, see 158. The inner sleeve 120 has an extension 122, which W O 97/15856 PCT~US96/17195 is beyond the top of the ringlight so that light ~rom the ~ibers cannot directly exit the illuminator 100.
Only light that is re~lected ~rom the re~lective surface 208 o~ the hood 200 is able to exit.
Figs. 4A, 4B, and 4C show alternative embodiments that enable adjustability in the angle of the light cone 152. As shown in Fig. 4A, the light reflecting sur~ace is machined to have a concave continuously curved or arcuate cross-section 208a. As a result, the angle ~ o~ the light cone 152 is dependent upon the location at which the incident beam 150 re~lects o~
the arcuate re~lecting surface 208a. This location is adjusted by changing the height of the ringlight 110 in the hood 200.
_ 15 Although the multiple dimples 113, 114 and bolt 212 o~ Figs. 2 and 3 are one solution to indexing the height o~ the ringlight, continuous adjustment is usually pre~erable in this embodiment. Thus, in one solution, a rack 172 is attached to the ringlight 110.
The rack 172 is engaged by a pinion gear 170 on the hood 200. The gear is then turned by an operator to change the height.
As a side note, it will be recognized that this embodiment works best with a tight, well collimated beam 150 ~rom the ringlight 110. Stray light will tend to be re~lected at divergent angles o~ o~ the arcuate sur~ace 208a which may blur the edges o~ the light cone 152.
Fig. 4B shows another embodiment 208b o~ the light re~lecting sur~ace. This embodiment also has an overall curved light re~lecting sur~ace but having two discrete angles to enable generation o~ light cones o~
two angles. Fig. 4C is still another embodiment also having two angles, but arranged in a generally convex con~iguration.
As shown in Fig. 5, the illuminator 100 may be modi~ied for ~he;nherg di~erential color illumination.
This is an extension of the dark field viewing in which the ~ield is given a desired color rather than simply being without light. In this application, the end cap 130 is replaced with a ~ield color ~ilter 160, and an integrating chamber 162 is placed below this ~ilter.
The chamber receives light from a second fiber optic bundle 164. Similar chambers or di~users are disclosed in U.S. Pat. No. 5,102,227, entitled "Lighting and Detection System", by Zwirner, et al.
The bundle 164 can be connected to a separate source o~
light, or i~ a splitter 166 is available, connected to light source 318.
The ~iltered light ~rom ~ilter 160 determines the color oi the ~ield. In many cases the color ~ilter 320 may be used to color the light to the ringlight 110 to enhance the di~ferential color between the specimen and the background as viewed in the microscope.
The light passing through the ~ilter 160 is pre~erably di~use. For some application, however, it may be pre~erable to generate hard edge outlines o~ the specimen by using a source o~ collimated light.
Fig. 6 is a perspective, exploded view o~ a ~urther embodiment o~ the inventive di~erential illumination system. As described previously, this embodiment also includes a hood 200 that fits over a ringlight 110. The hood is held in place by a bolt 212 that engages a dimple 113 on the ringlight 110. The inner sleeve 120 is press fit into the center bore 112 5 of the ringlight 110. This embodiment differs in that a glass or other transmissive material is placed over the aperture 206 in the hood 200. Preferably, the glass cover or stage 410 is placed in a recess 414 machined in the top of the hood. A retaining ring 412 is then bolted or screwed 413 to the hood 200 to hold the glass cover in place. This glass cover protects the inside ringlight from becoming dirty. When the cover 410 becomes dirty, however, it may be removed for cleaning. Optionally, the glass cover can be a filtering material for color filtering or polarization of the dark field light.
-other changes may be made. For example, although the invention is described in the context of microscope viewing, it is also applicable to differential illumination in serology, gemology, and machine vision applications and other similar imaging uses.
Backqround of the Invention Many diverse methods of optical imaging and assisted viewing reguire some type of specimen illumination. Microscopes magnify light from only a small area with a con~or;tant reduction in light intensity. This necessitates intense illumination of the specimen in order to provide adequate light levels for viewing. Machine vision applications often achieve better performance with intense illumination, which provides better resolution of the workpiece's or specimen's details. Identifying workpiece edges and surface features allows the position and orientation to be determined automatically.
-Generally the lighting can originate from in front o~ or behind the specimen. Microscopes commonly use backlighting with a light source below a specimen stage that directs light upward through a microscope slide held on the stage to its first optical element, or the microscope objective. This lighting configuration istypically used for a transparent or translucent specimen since the light must pass through the specimen to be captured by the microscope. Light sourced ~rom above the specimen is typically used with opaque specimens.
When lighting from above the specimen, a problem stems from the fact that a single point light source can not be located in line with the microscope~s optical axis without obstructing its view or a complex optical arrangement. The specimen is thus usually W O 97/15856 PCT~US96/17195 illuminated from light off the axis, but this can create shadows. The solution to this dilemma is a device termed a ringlight. This device i5 typically torroidal in shape to fit around the barrel of the microscope or similar optical apparatus. The barrel and ringlight are arranged so that the barrel i8 coextensive with the ringlight's axis. The ringlight emits light in a 3~0 degree circle in the general direction of its axis, but angling inward slightly.
This forms a cone of light having a vertex located on the axis. When used as a microscope light, for example, the specimen is illuminated evenly from all sides without shadows being visible through the microscope.
There are a number of variations on the backlighting theme. One such variation is a form of differential illumination termed dark ~ield illumination. Many specimens exhibit little or no contrast when viewed with ordinary backlighting because they are colorless and transparent. Chemical stA;n;ng is the typical solution in this situation, but in some cases it may be undesirable. In dark field illumination, the specimen is illuminated with a hollow cone of light aligned along the optical axis of the microscope and originating from below the specimen. The microscope objective is located within the dark base of the hollow light cone. Consequently, without a specimen, there is no illumination in the microscope.
A specimen placed on the stage, however, tends to diffract, reflect, and refract light of the cone, and this scattered light can then enter the objective.
When observed through the microscope, live bacteria, for example, are visible, their edges and internal structures being outlined by redirected light, which is collected by the microscope optics. Rheinberg dif~erential illumination is similar except that the field is given a desired color with diffuse lighting.
Summarv of the Invention The present invention concerns a differential ~ 5 illumination system that uses a ringlight or similar source of electromagnetic radiation. Light from the ringlight is redirected to form a cone of light projecting upward and away from the system. This enables dark field or Rheinberg illumination, for example. As a result, if desired the invention may be used to retrofit conventional ringlights, adapted for general purpose illumination, for these specialized techniques.
In general, according to one aspect, the invention _ 15 ~eatures an illumination system. The system comprises a ringlight having an annular light emitting portion and a hood that fits over the ringlight. The hood has an aperture and an annular reflective surface, disposed opposite the light emitting portion, that reflects the light from the ringlight through the aperture.
In specific embodiments, the ringlight receives light via a fiber optic bundle and the annular light emitting portion comprises a ring of these fibers from the bundle.
When adapted for di~ferential illumination such as dark field or Rheinberg illumination, an angle of the annular reflective sur~ace is selected relative to a direction of light from the ringlight to form a cone of light exiting the aperture. To ensure good contrast, a light baffle may be incorporated to prevent stray light from the ringlight from directly exitlng through the aperture. This baf~i~le is pre~erably ~ormed i~rom a sleeve inserted into a center bore o:E the ringlight.
If a di:E~use cone is desired, a dif~usion screen may be also added.
Further, a i~ield illumination light source may be added to emit a di~used light to enable the Rheinberg di~i~erential illumination.
In general, according to another aspect, the invention may also be characterized as a system i~or converting a ringlight, which is adapted :Eor conventional illumination, to provide di~:Eerential illumination. Such a system would comprise the hood that has been adapted to i~it over the ringlight to properly redirect the output :Erom it.
In general, according to another aspect, the invention may also be characterized as a method ~or converting a ringlight i~or di~erential illumination in a viewing device, such as a microscope. This method comprises blocking light ~rom the ringlight from being transmitted directly into the viewing device. The light i~rom the ringlight, however, is re~lected to ~orm a hollow cone o~ light. An objective of the viewing device is then placed within the hollow cone oE light.
This enables dark f~ield viewing since only structures within a specimen will direct light to the viewing device.
The above and other :Eeatures o~ the invention including various novel details o:E construction and combinations oi~ parts, and other advantages, will now be more particularly described with re~erence to the accompanying drawings and pointed out in the claims.
It will be understood that the particular method and device embodying the invention are shown by way o~
illustration and not as a limitation o~ the invention.
The principles and ~eatures o~ this invention may be employed in various and numerous embodiments without departing ~rom the scope o~ the in~ention.
~rie~ PescriPtion of the Drawinqs In the accompanying drawings, re~erence characters re~er to the same parts throughout the di~erent views.
The drawings are not necessarily to scale; emphasis has instead been placed upon illustrating the principles o~
the invention. 0~ the drawings:
Fig. 1 illustrates the prior art use o~ a ringlight as a light source positioned above the specimen;
- Fig. 2 is a perspective and exploded view o~ a di~erential illumination system o~ the present invention con~igured ~or dark ~ield illumination and showing a partial cut-away in the ringlight adaptor-re~1ector hood;
Fig. 3 is cross-sectional view o~ the inventive dark ~ield illuminator;
Figs. 4A, 4B, and 4C are partial cross-sectional views showing the illuminator with a modification ~or providing adjustment of the angle o~ the light cone;
Fig. 5 shows a modi~ication o~ the inventive illuminator ~or Rheinberg di~erential color illumination; and Fig. 6 is a perspective exploded view o~ another embodiment o~ the inventive system that has a removable cover.
Descri~tion of Pre:Eerred Embodiments Turning now to the drawings, Fig. 1 illustrates the typical application of a conventional ringlight as a microscope illuminator. The ringlight 110 is attached to the barrel o~ a microscope 50. It generates a cone of light 150 which is directed downward to the stage 310 to illuminate a specimen on slide 314. The ringlight itself typically receives light via a fiber optic cable 116 from a source 318.
Fig. 2 shows a dif~erential illumination system 100 based on the conventional ringlight 110 that has been constructed according to the principles of the present invention. The system 100 comprises a re~lector hood 200 that ~its over the ringlight llo.
An inner sleeve 120 is press fit into the center - aperture 112 of the ringlight 110. Finally, an end cap 130 covers a center cavity 132 defined by the inner surface o~ the sleeve 120 to ~orm a dark field stop at the bottom o~ the illuminator 100. This prevents light seepage into the center cavity 132.
In operation, the system 100 is located under a microscope stage 310 to illuminate a specimen 312 held on slide 314. The microscope objective 316 captures light for viewing by a user or imaged on a charge coupled device, for example.
The hood 200 is preferably constructed from machined aluminum and has a non-re~lecting, light absorbent, finish on most o~ its outer surfaces. Black anodization is one possible technique ~or achieving these sur~ace characteristics. The hood 200 is generally cylindrical with a bore 202 extending axially through the hood. The proximal end 204 o~ the bore is CA 022332ll l998-04-24 frustro-conical, a terminal end of which is a light emitting aperture 206. The frustro-conical portion of the bore yields an inner chamfered surface 208 that is polished for maximum light reflectance. The light reflecting surface 208 is angled at approximately 45 degrees, preferably 42 degrees with respect to the central axis 102. The distal end 210 of the bore is essentially cylindrical and is sized to receive the ringlight 110.
The ringlight 110 is installed into the distal end 210 o~ the bore. In one embodiment it is held in place by a bolt 212 threaded into the hood 200 and engaging a dimple 113 in the outer suri~ace of ringlight 110.
Indexing may be provided by forming multiple dimples 114 axially along the outer surface of the ringlight - 110 to enable height adjustment of the ringlight 110 within the hood 200.
The ringlight 110 is preferably a fiber optic type light system such as the Dolan-Jenner ringlight Model No. A3739P. A fiber optic bundle 116 connects to receive light from a light source 318. The bundle 116 may be glass, plastic or quartz fibers, to list a ~ew alternatives. At the point of connection a light ~ilter 320 can be added to adapt the color oE the light for Rheinberg dii~ferential color illumination, for example. Light from the source 318 is coupled into the bundle 116 and transmitted to the ringlight 110.
There, the individual fibers 118 are separated and dispersed evenly around the circumference of the ringlight. The terminal end 119 of the fibers 118 are aligned generally axially but angled lnward slightly, .
WO 97tl5856 PCTAUS96/17195 18 degrees in the particular ringlight illustrated, to generate a cone of light 150 having an acute angle vertex.
other types of ringlights are compatible with the invention. For example, using a circle of light emitting diodes on the housing of the ringlight might be preferred in applications in which it is dif~icult to accommodate the thick fiber optic bundle 116.
As best shown in Fig. 3, the light 150 emitted ~rom the ringlight is re~lected o~ of the light re~lective surface 208 o~ the hood 200. The light then travels out through the light emitting aperture 206.
The light exiting the aperture is substantially 25 degrees from horizontal. The result is a hollow light _ 15 cone 152 projecting upward ~rom the aperture 206. The trajectory of the light is such that it will not enter the light collection optics 316 of the imaging device, the microscope objective. The specimen 312 placed on the slide 314 will tend to reflect, refract, and di~ract light toward the microscope objective 116, however.
In some applications, a more di~use light cone may be desirable. A diffusion screen 168 may be added in these cases. The pre~erred location is across the aperture 206.
The inner sleeve 120 functions as a light ba~fle.
Good contrast in dark ~ield illumination requires keeping light from the illuminator 100 only in the hollow cone 152. The ~ibers, however, tend to emit a portion o~ the light of~ o~ their central axes, see 158. The inner sleeve 120 has an extension 122, which W O 97/15856 PCT~US96/17195 is beyond the top of the ringlight so that light ~rom the ~ibers cannot directly exit the illuminator 100.
Only light that is re~lected ~rom the re~lective surface 208 o~ the hood 200 is able to exit.
Figs. 4A, 4B, and 4C show alternative embodiments that enable adjustability in the angle of the light cone 152. As shown in Fig. 4A, the light reflecting sur~ace is machined to have a concave continuously curved or arcuate cross-section 208a. As a result, the angle ~ o~ the light cone 152 is dependent upon the location at which the incident beam 150 re~lects o~
the arcuate re~lecting surface 208a. This location is adjusted by changing the height of the ringlight 110 in the hood 200.
_ 15 Although the multiple dimples 113, 114 and bolt 212 o~ Figs. 2 and 3 are one solution to indexing the height o~ the ringlight, continuous adjustment is usually pre~erable in this embodiment. Thus, in one solution, a rack 172 is attached to the ringlight 110.
The rack 172 is engaged by a pinion gear 170 on the hood 200. The gear is then turned by an operator to change the height.
As a side note, it will be recognized that this embodiment works best with a tight, well collimated beam 150 ~rom the ringlight 110. Stray light will tend to be re~lected at divergent angles o~ o~ the arcuate sur~ace 208a which may blur the edges o~ the light cone 152.
Fig. 4B shows another embodiment 208b o~ the light re~lecting sur~ace. This embodiment also has an overall curved light re~lecting sur~ace but having two discrete angles to enable generation o~ light cones o~
two angles. Fig. 4C is still another embodiment also having two angles, but arranged in a generally convex con~iguration.
As shown in Fig. 5, the illuminator 100 may be modi~ied for ~he;nherg di~erential color illumination.
This is an extension of the dark field viewing in which the ~ield is given a desired color rather than simply being without light. In this application, the end cap 130 is replaced with a ~ield color ~ilter 160, and an integrating chamber 162 is placed below this ~ilter.
The chamber receives light from a second fiber optic bundle 164. Similar chambers or di~users are disclosed in U.S. Pat. No. 5,102,227, entitled "Lighting and Detection System", by Zwirner, et al.
The bundle 164 can be connected to a separate source o~
light, or i~ a splitter 166 is available, connected to light source 318.
The ~iltered light ~rom ~ilter 160 determines the color oi the ~ield. In many cases the color ~ilter 320 may be used to color the light to the ringlight 110 to enhance the di~ferential color between the specimen and the background as viewed in the microscope.
The light passing through the ~ilter 160 is pre~erably di~use. For some application, however, it may be pre~erable to generate hard edge outlines o~ the specimen by using a source o~ collimated light.
Fig. 6 is a perspective, exploded view o~ a ~urther embodiment o~ the inventive di~erential illumination system. As described previously, this embodiment also includes a hood 200 that fits over a ringlight 110. The hood is held in place by a bolt 212 that engages a dimple 113 on the ringlight 110. The inner sleeve 120 is press fit into the center bore 112 5 of the ringlight 110. This embodiment differs in that a glass or other transmissive material is placed over the aperture 206 in the hood 200. Preferably, the glass cover or stage 410 is placed in a recess 414 machined in the top of the hood. A retaining ring 412 is then bolted or screwed 413 to the hood 200 to hold the glass cover in place. This glass cover protects the inside ringlight from becoming dirty. When the cover 410 becomes dirty, however, it may be removed for cleaning. Optionally, the glass cover can be a filtering material for color filtering or polarization of the dark field light.
-other changes may be made. For example, although the invention is described in the context of microscope viewing, it is also applicable to differential illumination in serology, gemology, and machine vision applications and other similar imaging uses.
Claims (14)
1. An illumination system comprising a ringlight (110) having an annular light emitting portion and a hood (200) having an aperture (206) and an annular reflective surface (208) disposed opposite the light emitting portion for reflecting the light from the ringlight directly through the aperture, characterized in that the system further comprises:
a sleeve (120) that is inserted into a center bore (112) of the ringlight and that has an extension (122) projecting past the annular light emitting portion toward the annular reflective surface to function as a light baffle (122) for preventing light from the ringlight from directly exiting through the aperture.
a sleeve (120) that is inserted into a center bore (112) of the ringlight and that has an extension (122) projecting past the annular light emitting portion toward the annular reflective surface to function as a light baffle (122) for preventing light from the ringlight from directly exiting through the aperture.
2. An illumination system as described in Claim 1, wherein the ringlight receives light via a fiber optic bundle (116).
3. An illumination system as described in any one of the preceding claims, wherein the annular light emitting portion comprises a ring of fibers (119) from the fiber optic bundle.
4. An illumination system as described in any one of the preceding claims, wherein an angle of the annular reflective surface is selected relative to a direction of light from the ringlight to form a cone of light exiting the aperture.
5. An illumination system as described in any one of the preceding claims, further comprising a field illumination light source (162) for emitting light parallel to an axis of the ringlight.
6. An illumination system as described in any one of the preceding claims, wherein the distance between the ringlight and the annular reflective surface is adjustable.
7. An illumination system as described in any one of the preceding claims, wherein the annular reflective surface is curved to change an angle of the light exiting the aperture in response to changes in the distance between the ringlight and the reflective surface.
8. An illumination system as described in Claim 9, wherein the reflective surface has a continuous curvature.
9. A system for converting a ringlight (110) for differential illumination, comprising a hood (200) adapted to fit over the ringlight, the hood having an aperture (206) and an annular reflective surface (208) to be disposed opposite to an annular light emitting portion of the ringlight to directly reflect light from the ringlight through the aperture, characterized in that the system further comprises a sleeve (120) that is inserted into a center bore (112) of the ringlight and that has an extension (122) projecting past the annular light emitting portion of the ringlight toward the annular reflective surface to function as a light baffle (122) for preventing light from the ringlight from directly exiting through the aperture.
10. A system as described in Claim 9, wherein an angle of the annular reflective surface is selected relative to a direction of light from the ringlight to generate a cone of light exiting the aperture.
11. A system as described in any one of Claims 9-10, further comprising a field illumination light source (162) for emitting light parallel to an axis of the ringlight.
12. A system as described in Claim 11, further comprising a filter (160) for changing a color of the light from the light source.
13. A method for converting a ringlight for differential illumination for viewing device, the method comprising:
blocking light from the ringlight from being transmitted directly into the viewing device with a sleeve (120) that is inserted into a center bore (112) of the ringlight and that has an extension projecting past an annular light emitting portion of the ringlight toward an annular reflective surface to function as a light baffle (122);
reflecting the light from the ringlight with the annular reflective surface disposed opposite the annular light emitting portion to form a hollow cone of light; and positioning an objective of the viewing device within the hollow cone of light.
blocking light from the ringlight from being transmitted directly into the viewing device with a sleeve (120) that is inserted into a center bore (112) of the ringlight and that has an extension projecting past an annular light emitting portion of the ringlight toward an annular reflective surface to function as a light baffle (122);
reflecting the light from the ringlight with the annular reflective surface disposed opposite the annular light emitting portion to form a hollow cone of light; and positioning an objective of the viewing device within the hollow cone of light.
14. A method as described in Claim 13, further comprising emitting light within the hollow cone of light from the ringlight.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US08/547,507 US5820250A (en) | 1995-10-24 | 1995-10-24 | Dark field illuminator ringlight adaptor |
| US08/547,507 | 1995-10-24 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2233211A1 true CA2233211A1 (en) | 1997-05-01 |
Family
ID=24184922
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002233211A Abandoned CA2233211A1 (en) | 1995-10-24 | 1996-10-24 | Dark field illuminator ringlight adaptor |
Country Status (7)
| Country | Link |
|---|---|
| US (2) | US5820250A (en) |
| EP (1) | EP0857316B1 (en) |
| JP (1) | JPH11514458A (en) |
| AU (1) | AU7477596A (en) |
| CA (1) | CA2233211A1 (en) |
| DE (1) | DE69619253T2 (en) |
| WO (1) | WO1997015856A1 (en) |
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| US5820250A (en) * | 1995-10-24 | 1998-10-13 | Dolan-Jenner Industries, Inc. | Dark field illuminator ringlight adaptor |
| KR100278477B1 (en) * | 1997-10-24 | 2001-03-02 | 윤종용 | Optical microscope |
| US6271963B1 (en) * | 1998-01-16 | 2001-08-07 | Daniel Freifeld | Microscope illuminator for cylindrical objects |
| DE19903486C2 (en) * | 1999-01-29 | 2003-03-06 | Leica Microsystems | Method and device for the optical examination of structured surfaces of objects |
| US6341878B1 (en) * | 1999-08-31 | 2002-01-29 | Cognex Corporation | Method and apparatus for providing uniform diffuse illumination to a surface |
| US7604361B2 (en) | 2001-09-07 | 2009-10-20 | Litepanels Llc | Versatile lighting apparatus and associated kit |
| US6749310B2 (en) * | 2001-09-07 | 2004-06-15 | Contrast Lighting Services, Inc. | Wide area lighting effects system |
| US7331681B2 (en) | 2001-09-07 | 2008-02-19 | Litepanels Llc | Lighting apparatus with adjustable lenses or filters |
| US7083298B2 (en) | 2001-10-03 | 2006-08-01 | Led Pipe | Solid state light source |
| GB0227872D0 (en) * | 2002-11-28 | 2003-01-08 | Dunning Keith J | Microscope |
| DE10357496A1 (en) * | 2002-12-09 | 2004-07-01 | Carl Zeiss | Surgical operation microscope for use in operating theatre has binocular optical system with single large objective lens, peripheral lighting system and radio transmission of data |
| JP2005003995A (en) * | 2003-06-12 | 2005-01-06 | Olympus Corp | Dark-field illuminator |
| ATE479124T1 (en) * | 2004-04-16 | 2010-09-15 | Univ Auburn | MICROSCOPE ILLUMINATION DEVICE AND ADAPTER THEREOF |
| US7344273B2 (en) | 2005-03-22 | 2008-03-18 | Binary Works, Inc. | Ring light with user manipulable control |
| DE102005047593A1 (en) * | 2005-10-05 | 2007-04-12 | Carl Zeiss Jena Gmbh | Device for variation and adjustment of transmitted light illumination for microscopes |
| US7551349B2 (en) * | 2005-12-01 | 2009-06-23 | Auburn University | High resolution optical microscope with cardioid condenser for brightfield and darkfield illumination |
| WO2007070382A2 (en) * | 2005-12-09 | 2007-06-21 | Auburn University | Simultaneous observation of darkfield images and fluorescence using filter and diaphragm |
| WO2007098137A2 (en) * | 2006-02-20 | 2007-08-30 | Auburn University | Applications for mixing and combining light utilizing a transmission filter, iris, aperture apparatus |
| CN100451631C (en) * | 2006-03-24 | 2009-01-14 | 华南理工大学 | PCB drill bit image detecting and illuminating device |
| DE102006018410A1 (en) | 2006-04-20 | 2007-10-25 | Carl Zeiss Microimaging Gmbh | Contrast enhancement device for ring light illuminators |
| US20080062424A1 (en) * | 2006-09-07 | 2008-03-13 | Mark Richard Shires | Compact Ringlight |
| JP5022700B2 (en) * | 2006-12-27 | 2012-09-12 | 株式会社東芝 | Ultrasonic diagnostic equipment |
| US8854734B2 (en) * | 2009-11-12 | 2014-10-07 | Vela Technologies, Inc. | Integrating optical system and methods |
| JP5646922B2 (en) * | 2010-09-03 | 2014-12-24 | 株式会社トプコン | Inspection device |
| EP2986891A4 (en) * | 2014-04-04 | 2017-06-14 | Bio-rad Laboratories, Inc. | Annular illumination structure |
| US11385452B2 (en) | 2015-03-13 | 2022-07-12 | Genea Ip Holdings Pty Limited | Method and apparatus for microscopy |
| CN105278091B (en) * | 2015-11-20 | 2018-01-23 | 西南大学 | monochromatic field microscope illumination system |
| CN106932399B (en) * | 2015-12-30 | 2020-02-18 | 上海微电子装备（集团）股份有限公司 | Dark field lighting device and surface defect detection device |
| DE102016122102A1 (en) * | 2016-11-17 | 2018-05-17 | Westfälische Wilhelms-Universität Münster | Protective cap for an imaging device |
| US11733172B2 (en) * | 2020-05-15 | 2023-08-22 | Kla Corporation | Apparatus and method for rotating an optical objective |
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| US4160578A (en) * | 1978-04-17 | 1979-07-10 | American Optical Corporation | Annular reflector for microscope objective |
| BE875482A (en) * | 1979-04-11 | 1979-10-11 | Chandesais Jean L J | IMPROVED RING LIGHT FOR MICROSBUIES |
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| US4626079A (en) * | 1984-04-13 | 1986-12-02 | Nippon Kogaku K.K. | Dark field illumination apparatus for epi-illumination system |
| DE3442218A1 (en) * | 1984-11-19 | 1986-05-28 | Fa. Carl Zeiss, 7920 Heidenheim | LIGHTING LIGHTING DEVICE FOR MICROSCOPE |
| US4706168A (en) * | 1985-11-15 | 1987-11-10 | View Engineering, Inc. | Systems and methods for illuminating objects for vision systems |
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| US4974094A (en) * | 1989-12-04 | 1990-11-27 | Yuhkoh Morito | Direct lighting/illuminating system for miniature CCD camera |
| US5325231A (en) * | 1991-03-22 | 1994-06-28 | Olympus Optical Co., Ltd. | Microscope illuminating apparatus |
| US5268749A (en) * | 1991-07-26 | 1993-12-07 | Kollmorgen Corporation | Apparatus and method for providing uniform illumination of a sample plane |
| US5820250A (en) * | 1995-10-24 | 1998-10-13 | Dolan-Jenner Industries, Inc. | Dark field illuminator ringlight adaptor |
-
1995
- 1995-10-24 US US08/547,507 patent/US5820250A/en not_active Expired - Fee Related
-
1996
- 1996-10-24 AU AU74775/96A patent/AU7477596A/en not_active Abandoned
- 1996-10-24 CA CA002233211A patent/CA2233211A1/en not_active Abandoned
- 1996-10-24 WO PCT/US1996/017195 patent/WO1997015856A1/en active IP Right Grant
- 1996-10-24 EP EP96937002A patent/EP0857316B1/en not_active Expired - Lifetime
- 1996-10-24 DE DE69619253T patent/DE69619253T2/en not_active Expired - Fee Related
- 1996-10-24 JP JP9516840A patent/JPH11514458A/en active Pending
-
1998
- 1998-09-18 US US09/156,114 patent/US5997164A/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| WO1997015856A1 (en) | 1997-05-01 |
| JPH11514458A (en) | 1999-12-07 |
| AU7477596A (en) | 1997-05-15 |
| EP0857316A1 (en) | 1998-08-12 |
| DE69619253D1 (en) | 2002-03-21 |
| US5820250A (en) | 1998-10-13 |
| EP0857316B1 (en) | 2002-02-13 |
| DE69619253T2 (en) | 2002-10-17 |
| US5997164A (en) | 1999-12-07 |
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Legal Events
| Date | Code | Title | Description |
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| EEER | Examination request | ||
| FZDE | Dead |