Patent Grant
9429740
The present invention relates to a telecentric modular zoom system for mapping an object plane on a sensor, in particular in a digital transmitted light microscope or incident light microscope having interchangeable lenses, comprising a fixed tube lens unit and multiple optical assemblies, at least two of which are adjustable arranged relative to one another for the purpose of changing the magnification.
Digital microscopes are known per se. Unlike conventional light microscopes, the image of the sample being examined with digital microscope systems is not observed through an eyepiece, but rather is initially converted electro-optically using a digital image recording device and is visually reproduced again with the aid of an image display device—or the image content is evaluated electronically. In this arrangement, observation and evaluation are not tied to the place of image recording, but are instead freely selectable independently thereof owing to the possibility of transmitting electronic image signals. Thus, for example, an optimum adaptation to the physical constitution of an observer is possible just as is the transmission of an image over communication paths to multiple observation or evaluation locations, or the adaptation of the microscope to observational tasks that cannot be solved with conventional microscopes.
Telecentric zoom systems are used where variation in magnification is involved. In WO 2010/081678 A1, for example, a variable telecentric microscopy system is described in which at least one of the groups of lenses of the magnification system is adjustable along its optical axis, the position of the entry pupil remaining constant over the entire magnification range and being mapped at a physical location after the last mobile lens group. The drawback of this solution is the short infinite space between objective and zoom, which hampers coupling of the imaging light in this space and prevents the use of contrasts such as DIC in this space. Also desirable is a shortening of the overall transmission length.
Commercially available digital microscopes or microscope systems are constructively adapted to certain applications and are therefore generally unalterably designed as upright or inverted microscopes. Refitting for changing applications, which requires in each case a different type of microscope upright or inverted is either impossible altogether, or is possible only at disproportionately high expense.
Based on this state of the art, the object of the invention is to further develop a telecentric modular zoom system of the kind described above in such a way that when using interchangeable objectives and when varying the magnification with these objectives, telecentricity is ensured over the entire zoom range and, given a constant object-image distance, a variation in magnification (ratio of image size to object size), caused by an axial adjustment of the optical assemblies, is continuously possible.
This object is achieved according to the invention by the features of claim 1. Advantageous embodiments are specified in the subclaims 2 to 22.
In this arrangement a physical aperture conjugated relative to the rear focal points of the objectives used and having a variable diameter may be arranged in the beam path, whereby the rear focal points of the objective may be mapped in the space between a sensor image and an intermediate image, and the intermediate image, the images of the rear focal points of the objective and the sensor image do not lie within or migrate through the lens group.
The diameter of the image plane (sensor plane) in such case is ≧11 mm.
Furthermore, the minimum distance between the of the aperture plane on the objective side and the first vertex of the lens group configured as a tube lens unit is ≧25 mm.
The zoom system according to the invention enables magnifications with the zoom factors 10×0.5−5, and 8×0.5−3.2.
The scope of application lies in the visual spectral range of 436 nm to 644 nm.
The aperture is advantageously axially movable and is variable in diameter.
The following relation applies to the aperture in the aperture plane:
diameter of aperture min≧diameter of aperture max/3,
in which the diameter of the aperture min is set at a magnification min and the diameter of the aperture max is set at a magnification max.
The refractive power distributions and movement characteristics allow images to be mapped completely within an air space and therefore physically over the zoom range.
In a first advantageous embodiment having four optical assemblies, the invention, starting on the object side, consists of:
This variant is especially suitable for a telecentric zoom with an iris aperture m and coaxial reflected light.
The infinite space between aperture plane and first lens and the ratio of aperture chamber/aperture diameter >1.5 allows a beam splitter and other elements necessary for contrasting to be integrated. The low maximum beam inclination (arc tangent (½*11)/164.5*0.5))<4° in this space prevents any adverse effect by the components. There are two possible designs, one with an iris at the point of the aperture BLE for objectives having a rear focal point behind the objective and one with an iris at the conjugated point BL for objectives having a rear focal point inside the objective.
The mapping on a camera of relatively short design occurs at a low beam inclination. The conjugated aperture plane is accessible for the indicated physical aperture and the virtual aperture located in the microscope objective.
The maximum aperture diameter in this variant embodiment is 20 mm.
In a second advantageous embodiment having 5 optical assemblies, the invention, starting on the object side, consists of
In a third advantageous embodiment having five optical assemblies, the invention, starting on the object side, consists of:
In a fourth advantageous embodiment having five optical assemblies, the invention, starting on the object side, consists of:
In a fifth advantageous embodiment having seven optical assemblies, the invention, starting on the object side, consists of:
In a sixth advantageous embodiment having six optical assemblies, the invention, starting on the object side, consists of:
In a seventh advantageous embodiment having five optical assemblies, the invention, starting on the object side, consists of:
In an eighth advantageous embodiment having six optical assemblies, the invention, starting on the object side, consists of:
This variant having the fixed apertures after the zoom means the exit pupil is in a constant position and creates favorable opportunities for coupling to the following optics such as, for example, a laser scanning assembly. The aperture plane is suitable for coupling axial incident light to a constant light guidance factor and for pupil interferences.
The modular zoom system according to the invention is described in more precise detail below with reference to several examples. In the related drawings:
The zoom system according to the invention shown in
Starting from the object side, i.e. from the aperture plane BLE, the zoom system is characterized by the fixed optical assembly LG1 (tube lens unit), the movable assembly LG2, a movable intermediate image ZB, the movable assembly LG3, a movable aperture BL, the fixed assembly LG4 and the image plane (sensor plane) BIE.
The movement characteristics of the zoom system from
In this case, the magnification β is equal to the focal length zoom/focal length of a reference tube lens (164.5 mm).
The zoom system according to the invention in
Starting from the object side, i.e. the image plane BLE, the zoom system is characterized by the fixed optical assembly LG1 (tube lens unit), the movable assembly LG2 (field lens unit), a movable intermediate image ZB, the movable assembly LG3, a movable aperture BL, the movable assembly LG4, the fixed assembly LG5 and the image plane (sensor plane) BIE.
The movement characteristics of the zoom system from
In this case, the magnification β is equal to the focal length zoom/focal length of a reference tube lens (164.5 mm).
The zoom system according to the invention in
Starting from the object side, i.e. the image plane BLE, the zoom system is characterized by the fixed optical assembly LG1 (tube lens unit), the fixed assembly LG2, a fixed intermediate image ZB, the movable assembly LG3, a movable aperture BL, the movable assembly LG4, the movable assembly LG5 and the image plane (sensor plane) BIE.
The movement characteristics of the zoom system from
In this case, the magnification β is equal to the focal length zoom/focal length of a reference tube lens (164.5 mm).
The zoom system according to the invention in
Starting from the object side, i.e. the image plane BLE, the zoom system is characterized by the fixed optical assembly LG1 (tube lens unit), the movable assembly LG2 (field lens), a movable intermediate image ZB, the movable assembly LG3, a movable aperture BL, coupled to the movable assembly LG4, the fixed assembly LG5 and the image plane (sensor plane) BIE.
The movement characteristics of the zoom system from
In this case, the magnification β is equal to the focal length zoom/focal length of a reference tube lens (164.5 mm).
The zoom system according to the invention in
Starting from the object side, i.e. the image plane BLE, the zoom system is characterized by the fixed optical assembly LG1 (tube lens unit), a fixed field lens FL1, a fixed intermediate image ZB, a second fixed field lens FL2, the movable assembly LG2, a movable aperture BL, which is coupled to the movable assembly LG3, the movable assembly LG4, a fixed field lens FL3 and the image plane (sensor plane) BIE.
The movement characteristics of the zoom system from
In this case, the magnification β is equal to the focal length zoom/focal length of a reference tube lens (164.5 mm).
The zoom system according to the invention in
Starting from the object side, i.e. the image plane BLE, the zoom system is characterized by the fixed optical assembly LG1 (tube lens unit), the fixed assembly LG2 (field lens), a fixed intermediate image ZB, the fixed assembly LG3 (field lens), the movable assembly LG4, a movable aperture BL, which is coupled to the movable assembly LG5, the movable assembly LG6 and the image plane (sensor plane) BIE.
The movement characteristics of the zoom system from
In this case, the magnification β is equal to the focal length zoom/focal length of a reference tube lens (164.5 mm).
The zoom system according to the invention in
Starting from the object side, i.e. the image plane BLE, the zoom system is characterized by the fixed optical assembly LG1 (tube lens unit), the fixed assembly LG2 (field lens), a fixed intermediate image ZB, a fixed field lens FL, the two-part movable assembly LG3, a movable aperture BL, the movable assembly LG4 and the image plane (sensor plane) BIE.
The movement characteristics of the zoom system from
In this case, the magnification β is equal to the focal length zoom/focal length of a reference tube lens (164.5 mm).
The zoom system according to the invention in
Starting from the object side, i.e. the image plane BLE, the zoom system is characterized by the fixed optical assembly LG1 (tube lens unit), the movable assembly LG2, a movable intermediate image ZB, the movable assembly LG3, the movable assembly LG4, the fixed assembly LG5, a fixed aperture BL, the fixed assembly LG6 and the image plane (sensor plane) BIE.
The movement characteristics of the zoom system from
In this case, the magnification β is equal to the focal length zoom/focal length of a reference tube lens (164.5 mm).
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2013 006 999 | Apr 2013 | DE | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 6292306 | Betensky | Sep 2001 | B1 |
| Number | Date | Country |
|---|---|---|
| 1 061 741 | Mar 1967 | GB |
| WO-2010081678 | Jul 2010 | WO |
| Entry |
|---|
| Search Report, German Patent and Trademark Office, German Patent Application No. 10 2013 006 999.8, dated Jun. 26, 2013. |
| Number | Date | Country | |
|---|---|---|---|
| 20140313589 A1 | Oct 2014 | US |
