Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B21/00—Microscopes
  • G02B21/18—Arrangements with more than one light path, e.g. for comparing two specimens
  • G02B21/20—Binocular arrangements

Definitions

• the invention relates to a microscope tube, which is designed for coupling to an infinite beam path of a microscope and has a tube lens that generates an intermediate image that can be viewed via binocular optics.
• Such microscope tubes are known.
• DE 195 138 70 A1 describes a microscope tube with a tube lens, which transmits the image into an intermediate image plane of an eyepiece and has a corresponding deflection device in order to enable easy viewing of the image via a binocular lens.
• This microscope tube is designed such that the angle by which the beam path is deflected can be adjusted over a wide angular range by means of a prism and a rotatable mirror. This makes it possible to adjust the viewing angle from which a viewer can see into the microscope tube.
• an intermediate tube is provided as a modular, separate component in DE 198 285 48 A1, which can be connected upstream of the microscope tube carrying the binocular optics in the infinity beam path of a microscope.
• This intermediate tube allows height adjustment, so that in combination with the tube known from DE 195 138 70 A1 with adjustable viewing angle, both the angle and the height of the tube viewing can be adjusted over a wide range.
• a microscope tube with an entrance optic, which is designed for coupling to an infinite beam path of a microscope, a tube lens, which brings bundles of rays supplied by the spaced entrance optics together in an intermediate image, so that a finite light beam path is formed between the tube lens and the intermediate image, and a prism unit arranged downstream of the tube lens, which deflects the further beam path by a fixed angle between 65 ° and 75 ° and lies in the finite beam path in such a way that the intermediate image can be viewed without further intermediate images with binocular optics that can be attached to the upper part of the housing, with a height adjustment device being provided the distance between the entrance optics and the tube lens is adjustable.
• the invention therefore turns away from the previously usual procedure, in which a microscope tube that was as universally adjustable as possible was sought. Instead, a fixed viewing angle of approximately 20 ° is now provided, which is combined with a height adjustment. Such a fixed viewing angle was recognized as ergonomically more favorable, since the wide adjustability of the viewing angle according to the prior art regularly led to incorrect settings by the users. In order to be able to optimally select the height of the tube insight, this fixed viewing angle in the microscope tube is combined with an integrated height adjustment device.
• This combination according to the invention - selection of a fixed viewing angle close to 20 ° and the greatest possible adjustability of the altitude - makes it possible to avoid the solution, which is more complex in terms of construction and production technology, with a modular intermediate tube.
• the integration of the height adjustment device in the microscope tube housing achieves manufacturing advantages, so that such a microscope tube is less expensive.
• the microscope tube is smaller, in particular shorter. This avoids an unergonomically large distance between the tube view and the focusing knobs of a microscope.
• the prism unit provided in the housing effects the beam deflection required for the ergonomically favorable viewing angle.
• a deflection angle which is defined as a supplementary angle between the original optical axis and after the deflection of the present optical axis, between 65 ° and 75 ° has proven to lead to a particularly ergonomic viewing angle.
• the invention provides a microscope tube with a housing, which has an upper housing part and a lower housing part, in which the entrance optics is attached while the upper housing part carries the tube lens, which lies with the entrance optics on a common optical axis, the upper housing part and lower housing part being displaceable relative to one another along the optical axis.
• This two-part housing is particularly small and advantageously accommodates the height adjustment device.
• the microscope tube according to the invention has the further advantage that different prism units can be used without major structural changes to the other components.
• a microscope tube with a prism unit is preferably provided, which by a
• Double reflection does not change the image position.
• a prism unit having a first and a second prism, which are spaced apart by an air gap, is particularly expedient, the beam bundle entering the first prism first totally reflecting on its surface assigned to the air gap and then on an adjacent, mirrored surface reflected second prism.
• Such a prism structure has the advantage that the resulting optical path length is extremely short. It can therefore also be used advantageously for tube lenses with a short focal length.
• a prism unit is therefore advantageous for such an application, which combines a unique reflection for reversing the height with a corresponding device for reversing the side. This is achieved in a particularly simple manner by a prism unit which effects an image position inversion and, for this purpose, has a pair of reflective roof surfaces which, as is known, results in a page reversal.
• the height adjustment device must make the distance between the tube lens and the entrance optics, with which the bundles of rays are picked up from the infinite beam path of the microscope, variable, whereby the optics downstream of the tube lens always remain at a fixed distance from the tube lens.
• This is particularly easy to achieve, in particular in the case of afocal entrance optics, which are preferred for image correction reasons, by designing the housing in which a lower housing part can be telescopically pushed into an upper housing part if the lower housing part carries the entrance optics and the upper housing part carries the tube lens including subordinate optics .
• Known guide rods can be used to guide the unit carrying the entrance optics and the unit carrying the tube lens including the downstream optics.
• Particularly precise guidance is achieved with a recirculating ball bearing guide, in which a guide carriage preferably runs on a guide rail.
• Such a recirculating ball guide has the further advantage that inexpensive standard components can be used.
• any suitable fixation mechanism that counteracts an adjustment of the distance between the entrance optics and the tube lens is suitable for this purpose;
• appropriate closures are conceivable that block the adjustment mechanism, such as locking levers or the like.
• An adjustment mechanism that does not have to be blocked separately, but in which a certain force must always be overcome for adjustment, is particularly expedient.
• a particularly simple embodiment in this regard is a slip clutch which inhibits the height adjustment mechanism of the entrance optics and tube lens.
• a slip clutch In the case of an adjustment mechanism driven by a rotatable shaft, such a slip clutch will advantageously be provided between the shaft and a housing part in which the shaft is held.
• a shaft rotatably held in a housing part is provided, the rotation of which drives the mutual displacement of the entrance optics and the tube lens, a non-rotatably seated slider on the shaft, which is tensioned on a sliding surface attached to the housing part, so that a the rotation of the shaft inhibiting slip clutch is formed.
• This design requires few moving parts and only a few friction linings.
• the friction linings can have Teflon particularly advantageously, since they are particularly wear-resistant.
• a locking mechanism in particular in the form of a slip clutch, has the advantage that the selected altitude remains largely independent of the weight of the microscope tube or the weight that is placed on the microscope tube by a camera, for example.
• the tube lens together with the downstream optics, in particular together with the eyepiece is usually moved upwards in order to enlarge the distance between the entrance optics and the tube lens. A different force is then required to increase the distance than to reduce the distance between the entrance optics and the tube lens.
• the angle by which the prism unit deflects the beam path can be freely selected between 65 ° and 75 ° in the range according to the invention.
• a deflection angle close to or equal to 70 ° has proven to be particularly ergonomic, so that a viewing angle close to or equal to 20 ° is achieved when the optical axis is vertical.
• Cameras are often attached to microscopes to record images. It is particularly expedient that the camera then lies in the intermediate image plane of the tube lens. In principle, this could be done by attaching the camera to the eyepiece.
• the prism unit can be moved out of the beam path and a camera connection is provided, via which the intermediate image can be recorded with a camera attached to the camera connection when the prism unit is moved out, so that the intermediate image is imaged directly into a camera.
• the eyepiece can then remain in position with the camera installed and does not have to be removed.
• FIG. 1 is a perspective view of a microscope tube from above
• FIG. 2 is a perspective view of the microscope tube from below
• FIG. 3 is a longitudinal sectional view along the optical axis through the microscope tube
• FIG. 5 shows a further longitudinal sectional illustration of the microscope tube in the plane of the optical axis and of the adjustment mechanism
• FIG. 6 is a schematic illustration of a prism unit of the microscope tube
• Figure 7 shows an optional configuration of the prism unit.
• Figure 1 shows a perspective view of a microscope tube, which is intended for mounting on a tripod of a microscope.
• the microscope tube has a two-part housing with an upper housing part 2 and a lower housing part 3.
• a binocular part is attached to the upper housing part 3, which, as will be explained in more detail later, grants a viewing angle of 20 ° when the housing 1 of the microscope tube is mounted on a microscope with a vertically extending axis.
• two eyepiece inserts 5 and 6 are inserted, the distance between which can be adjusted to the eye relief of the user.
• the housing 1 of the microscope tube is adjustable in such a way that the lower housing part 3 can be pushed telescopically into the upper housing part 2. This telescopic movement is actuated via a height adjustment wheel 7. On the top of the housing 1, a cover 8 can also be seen, which is provided for a camera connection to be explained.
• Figure 2 shows the microscope tube in perspective from below.
• An entry optic 9 is provided in the bottom of the lower housing part 3, via which radiation from the infinite beam path of the microscope can be coupled.
• the lower housing part 3 also has threaded holes 10 on its base, via which the housing 1 can be screwed to the microscope stand.
• Figure 3 shows a sectional view of the inner structure of the microscope tube.
• a tube lens 12 Downstream of the entry optics 9 is a tube lens 12 which is fastened in a prism holder which carries a prism unit 13 arranged downstream of the tube lens 12.
• the tube lens 12 brings the tufts of rays, which are guided by the entry optics 9 in the infinity beam path, to an intermediate image, which is then visible through the binocular part 4.
• the prism unit 13 causes the beam path to be deflected by an angle of 70 °.
• the structure of the prism unit 13 will be explained in more detail later with reference to FIG. 6.
• a guide carriage 14 of a recirculating ball guide is fastened by screws 20 and runs on a guide rail 15 fastened to the upper housing part 2.
• the recirculating ball guide causes an exact vertical guidance of the lower housing part 3 relative to the upper housing part 2 along the optical axis OA1.
• the height d, d. H. the distance between the entrance optics 9 and tube lens 12 is maximum.
• the lower housing part 3 is inserted into the upper housing part 2, which, when the lower housing part 3 is fastened to a microscope stand, has the consequence that the viewing height with which a user of the microscope looks into the eyepiece inserts 5 and 6 decreases.
• the wall of the lower housing part runs into the upper housing part. This can be seen, for example, on the backdrop wall 16. So that the lower housing part 3 can be pushed as far as possible into the upper housing part until the entrance optics 9 are at a minimally permissible distance from the tube lens 12, a gap 39 is provided on the back of the binocular flange 19, which is located between the prism unit 13 and the binocular flange 19 and in which the backdrop wall 16 can be placed. The maximum insertion depth of the lower housing part 3 into the upper housing part 2 is thus determined by the distance between the lower edge of the upper housing part 2 and the upper edge of the gap 39.
• the gap 39 is therefore designed for the largest possible adjustment range so that the link wall 16 runs past the prism unit 13 without, however, in the optical Beam path to the binocular part 4, d. H. to coincide with the binocular opening 18.
• FIGS. 4 and 5 show different sectional representations through the microscope tube 1, each in the plane of this shaft 25.
• the shaft 25 is mounted in the upper housing part 1 and carries a driver piece 27, which is fastened in a rotationally fixed manner by means of a grub screw 31.
• the toothed wheel 32 engages in a toothed rack 30 fastened to the lower housing part 3, so that toothed rack 30 and toothed wheel 32 form a toothed rack drive for changing the height d.
• spring units 26 are clamped between the upper housing part 2 and the lower housing part 3, which the own weight of the Compensate upper housing part 2 and the attached binocular part 4.
• the tension of each spring unit 26 is preferably suitably adjustable in order to enable adaptations to binocular parts 4 of different weights. So that the same conditions prevail during upward and downward movement, the spring units have a very flat spring characteristic curve, which is chosen exactly so that it compensates for the weight of the moving parts, ie the upper housing part 2 together with the attached components.
• a slip clutch unit is additionally provided.
• this has a Teflon plate 28 which sits on a wall of the upper housing part 2.
• a friction disk 29, which can also be made of Teflon, is pressed onto this Teflon plate via a plate spring 33 lying on the shaft 25.
• the plate spring 33 is supported on a support plate 34 which is fixed on the shaft 25 and has an adjustable bias so that its holding force is adjustable.
• a clamping screw can also be used, whereby weights of up to 5 kg can be supported using conventional disc spring designs.
• the microscope tube 1 is designed so that different prism units can be used.
• the prism unit shown in FIG. 6 which has a two-part prism group. It consists of a Bauernfeind prism 21, which acts as a deflection prism. It has a mirror surface 24 on its vertical prism surface.
• An additional prism 22 lies above an air gap 23 of a few 1/10 mm from the Bauernfeind prism 21 and causes the beam path which passes obliquely through the air gap 23 to emerge from the prism unit on a surface perpendicular to the optical axis OA2.
• the length of the additional prism 23 allows the optical beam path to be shortened, since light paths covered in glass mean a shorter optical path length than the same distance in an air path.
• the fact that the air gap 23 is penetrated obliquely by the optical axis OA2 and thus by the beam path is not disadvantageous for the image quality. Since in the Bauernfeind prism 21 a total of two reflections take place at the air gap 23 and at the mirror surface 24, the original image position remains unchanged.
• a special glass is used, which enables total reflection through a suitable refractive index and at the same time ensures compliance with the tube lens focal length.
• the prism shown schematically in the perspective illustration of FIG. 7 can also be used, which causes an image inversion, ie a reversal of the image position with regard to height and side orientation.
• the prism unit is designed as a one-piece roof surface prism 38 which has an entry surface 36 perpendicular to the optical axis OA1 and an exit surface 37 perpendicular to the optical axis OA2.
• Two mirrored roof surfaces 38 effect the corresponding beam deflection. Since the beam path in the roof surface prism 35 only once reflected, there is a height inversion.
• the two roof surfaces 38 result in a side reversal at the same time.
• Both prisms deflect the beam path by approximately 70 °, so that the optical axis OA2 extends at an angle of approximately 20 ° to the horizontal when the optical axis OA1 is aligned vertically.
• the prism units 13 of Figures 6 and 7 are designed so that they can be used as interchangeable modules.
• one and the same microscope tube can, depending on the user's request, either show a correct image in the right side and height or a correspondingly inverted image on the binocular part 4. Extensive optical or mechanical changes are not necessary.
• the prism unit 13 In order to fasten a camera instead of the cover 8, a fastening device (not shown) is provided, the prism unit 13 also sits on a carriage (not shown) in order to be able to move it out of the beam path if an image is to be recorded with the camera ,

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• Physics & Mathematics (AREA)
• Chemical & Material Sciences (AREA)
• Analytical Chemistry (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Microscoopes, Condenser (AREA)
• Lens Barrels (AREA)
• Optical Elements Other Than Lenses (AREA)

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Citations (4)

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• 2001
  • 2001-06-26 DE DE10130621A patent/DE10130621B4/de not_active Expired - Fee Related
• 2002
  • 2002-05-13 EP EP02743001A patent/EP1399772A2/de not_active Withdrawn
  • 2002-05-13 US US10/481,653 patent/US20040240048A1/en not_active Abandoned
  • 2002-05-13 JP JP2003509222A patent/JP4431381B2/ja not_active Expired - Fee Related
  • 2002-05-13 WO PCT/EP2002/005252 patent/WO2003003099A2/de active Application Filing

Patent Citations (4)

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