US20040090671A1

US20040090671A1 - Comparison optical system

Info

Publication number: US20040090671A1
Application number: US10/694,690
Authority: US
Inventors: Manfred Gilbert
Original assignee: Leica Microsystems Wetzlar GmbH
Current assignee: Leica Microsystems CMS GmbH
Priority date: 2002-10-31
Filing date: 2003-10-28
Publication date: 2004-05-13
Also published as: EP1416308B1; EP1416308A1; DE50209087D1; US8009353B2; US20090180177A1; JP2004151732A; CN1499237A; CN100370305C

Abstract

A comparison optical system (1) comprising several image-acquiring optical subsystems is disclosed. A bridge (3) mechanically and optically connects the optical subsystems to one another. Each of the image-acquiring optical subsystems possesses an XYZ stage (8 a , 8 b), movable in motorized fashion, on which a sample to be examined is placed. Also provided is a control unit which moves the XYZ stages (8 a , 8 b), movable in motorized fashion, synchronously in all three spatial directions. The synchronous motion of the XYZ stages (8 a , 8 b) can be switched on and off by the user.

Description

RELATED APPLICATIONS

This application claims priority of the European patent application 02 102 514.3 which is incorporated by reference herein.

FIELD OF THE INVENTION

The invention concerns a comparison optical system. The invention concerns in particular a comparison optical system having several image-acquiring optical subsystems that are connected to one another via a bridge which mechanically and optically connects the several image-acquiring optical subsystems to one another.

BACKGROUND OF THE INVENTION

German Patent DE 30 06 379 discloses a defect inspection system for comparative inspection of a standard specimen and a test item. The test item and the standard specimen are on a common support, and both the standard specimen and the test item are imaged via optical means and combined so that a comparison is possible.

German Unexamined Application DE 41 03 457 describes a comparison microscope for viewing two similar specimens through two objectives, having a device which is configured for combining the two images for comparative viewing. Each of the two objectives is part of an individual microscope, a video mixing apparatus, to which the video signals of two video cameras acquiring the images from the microscopes are conveyed, being provided as the device for combining the two images. Synchronous displacement of the microscope stages has not been acknowledged.

U.S. Pat. No. 4,403,839 describes a comparison optical device that is embodied for simultaneous observation of two specimens. A bridge encompasses the optical means for combining the beam paths that are generated by the microscope or macroscope. Illuminating light is introduced into the system by means of the photo tube. The document does not mention how the individual specimens must be arranged on one or more stages.

These macroscopes or microscopes described above are used in corresponding systems, which are embodied as comparison microscopes or comparison macroscopes, for performing forensic comparative examinations. In a very well-known embodiment, two individual microscopes or individual macroscopes, connected to one another by a bridge, are used. The bridge contains an apparatus for combining the two individual images generated by the individual microscopes or macroscopes. Through a common tube arranged on the bridge, the operator of the comparison microscope or macroscope can view in superimposed fashion the images of specimens arranged on two different stages. Appropriate blocking of portions of the two samples corresponding to one another yields a composite image which makes possible a direct comparison, for example, of one sample half to the other sample half.

In forensic investigations, crime-solving often requires that an image of a first sample be compared to the image of a second sample in order to obtain more detailed information about the circumstances of a crime.

The specimens compared to one another are, for example, the impressions produced on cartridge cases by the firing pin of a weapon, in order to determine whether the same firearm was used in two or more crimes.

A further known application of optical comparison investigations consists in checking the authenticity of documents, especially banknotes, in order to determine whether they are counterfeit.

Lastly, crime-solving often requires comparing, for example, clothing fibers found at the crime scene to fibers of known articles of clothing, in order to obtain information about how a perpetrator was dressed at the time of a crime.

SUMMARY OF THE INVENTION

It is the object of the invention to create a comparison optical system that is configured in user-friendly fashion and provides reproducible results.

This object is achieved by way of a comparison optical system comprising:

several image-acquiring optical subsystems

a bridge which connects the several image-acquiring optical subsystems mechanically and optically to one another,

an XYZ stage, movable in motorized fashion, is provided for each image-acquiring optical subsystem, and

a control unit for moving the XYZ stages in motorized fashion, synchronously in all three spatial directions.

The above object is as well achieved by a comparison optical system comprising:

two macroscopes,

a bridge which connects the two macroscopes mechanically and optically to one another,

an XYZ stage, movable in motorized fashion, is provided for each macroscope, and

The above object is as well achieved by a comparison optical system comprising:

two microscopes,

a bridge which connects the two microscopes mechanically and optically to one another,

an XYZ stage, movable in motorized fashion, is provided for each microscope, and

The invention has the advantage that each image-acquiring optical subsystem possesses a XYZ stage, movable in motorized fashion, on which a sample to be examined is placed. Also provided is a control unit that moves the XYZ stages ( 8 a, 8 b), movable in motorized fashion, synchronously in all three spatial directions. If the comparison optical systems are embodied as macroscopes, the control unit is embodied as a control and adjustment apparatus on which is provided an on/off switch with which synchronous displacement of the XYZ stages can be switched on and off. Synchronous displacement has the advantage that upon actuation of an actuation element for a motion direction of an XYZ stage, both XYZ stages are displaced in exactly uniform synchronous fashion. The macroscopes can likewise each have associated with them a remote control device that can be used for stage and focus control. It is also possible to activate the stage and focus control systems of the two remote control devices in such a way that a synchronous motion is possible. The comparison optical system can likewise be constructed from microscopes. In this case a remote control device is connected to each microscope and can be activated so as to make possible, for example by actuation of an actuation element of the remote control device, synchronous displacement of the XYZ stages that are mounted on the microscope stand. The structures present on the specimens to be examined are often larger in terms of dimension than the region which is visible in the eyepiece or with the attached camera. In order to allow the entire specimen to be compared, both XYZ stages must be shifted synchronously in the X direction, Y direction, and Z direction. With synchronous displacement it is possible to shift the two XYZ stages synchronously using only one X actuation element or Y actuation element or the Z fine displacement control for each of the X, Y, and Z axes respectively. This has the advantage that evaluation of the specimens to be examined is considerably improved. A prerequisite for synchronization is that at least the three axes of the XYZ stages be motorized.

Further advantageous embodiments of the invention are evident from the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter of the invention is depicted schematically in the drawings and will be described below with reference to the Figures, in which: [0029]
FIG. 1 is a perspective view of a first embodiment of the comparison optical system, the optical subsystems being embodied as macroscopes; [0030]
FIG. 2 is a perspective view of a second embodiment of the comparison optical system, the optical subsystems being embodied as microscopes; and [0031]
FIG. 3 is a detail view of a control unit with which the XYZ stages of the comparison optical system are synchronously movable.[0032]

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a comparison optical system [0033] 1. In this embodiment, comparison optical system 1 comprises a first and a second macroscope 2 a and 2 b that are configured as image-acquiring optical subsystems. First and second macroscope 2 a and 2 b are mechanically and optically connected to one another via a bridge 3. Bridge 3 possesses a viewing port 4 for a user, and a tube 5 having a connection 6 for a camera (not depicted). Viewing port 4 for the user can be configured pivotably in order to maintain an ergonomic working position for the user. Tube 5 can additionally possess a further connection 7 with which, for example, a second camera (not depicted) can be attached. A first XYZ stage 8 a is associated with first macroscope 2 a. A second XYZ stage 8 b is associated with second macroscope 2 b. A specimen to be compared (not depicted) is placed respectively on first and on second XYZ stage 8 a and 8 b. In comparison macroscopy, both bullets and tools are assessed as specimens, and the traces left thereby are optically compared to one another and evaluated. This is done, in most cases, by splitting the image in the middle so that the specimen positioned on first XYZ stage 8 a is visible in the left half, and the specimen positioned on second XYZ stage 8 b is visible in the right half.
[0034] Bridge 3, together with first and second XYZ stage 8 a and 8 b, is mounted on a column 10 via a dovetail guide 11. By vertical displacement of column 10, bridge 3 is displaceable in the Z direction, or vertically, relative to the surface of XYZ stages 8 a and 8 b. The movement of bridge 3 allows coarse focusing of the specimens, present on the two stages 8 a and 8 b, whose structures are to be compared. Column 10 itself is joined to a base 12 which is substantially wider than column 10 in order to achieve sufficient stability and steadiness for comparison optical system 1. Arranged between the first and on the second XYZ stage 8 a and 8 b is a control and adjustment apparatus 14 with which various functions of comparison optical system 1 can be adjusted or modified. Control and adjustment apparatus 14 possesses several actuation elements (see FIG. 3 for description) with which various functions of comparison optical system 1 can be actuated. It is self-evident that control and adjustment apparatus 14 depicted in FIG. 1 can be variously embodied.
The two [0035] XYZ stages 8 a and 8 b are displaceable in the X direction, Y direction, and Z direction by way of several motors 16. A first and a second remote control device 18 a and 18 b can moreover also be associated with comparison optical system 1. In this embodiment, the first and a second remote control device 18 a and 18 b are each connected to comparison optical system 1 via a cable 19. Remote control devices 18 a and 18 b each possess a plurality of actuation elements 24 that can be assigned for various motorized functions of comparison optical system 1. It is self-evident that the connection can assume any technical configuration, for example radio, infrared, etc. Comparison optical system 1 can additionally have associated with it a PC 20 that, via an RS232 cable or USB cable 21, supplies control signals to comparison optical system 1 and receives image data or settings data from comparison optical system 1. The image data are displayed to the user on a monitor 22 that is connected to PC 20. The current settings data of comparison optical system 1 can also be displayed to the user on monitor 22.
FIG. 2 is a perspective view of a second embodiment of comparison optical system [0036] 1, the optical subsystems comprising, in this embodiment, a first and a second microscope 30 a and 30 b. Elements that correspond to the elements in FIG. 1 are labeled with the same reference characters. First and second microscope 30 a and 30 b are connected to one another via a bridge 3. Each microscope 30 a and 30 b comprises a stand that comprises a base 32. Base 32 is subdivided into three main segments, made up of a transverse main segment 34, a stand column segment 36, and a stand foot segment 35. An XYZ stage 8 a, 8 b is mounted on stand column segment 36. Each microscope 30 a and 30 b is equipped with a transmitted-light illumination system and an incident-light illumination system (both not depicted).
Stand [0037] foot segment 35 is convexly curved in the region facing toward stand column segment 36, and possesses a display 40 in convexly curved region 37. Display 40 can also be embodied as a touch screen which allows the user to make parameter inputs and call certain measurement methods therewith. If display 40 is not embodied as a touch screen, current settings data of the respective microscope 30 a or 30 b are then visually presented via display 40. Additionally mounted on each microscope 30 a and 30 b is a respective drive knob 42 which, for example, displaces XYZ stage 8 a or 8 b associated with each microscope 30 a or 30 b vertically (in the Z direction). It is likewise conceivable additionally to assign other functions to drive knob 42. Multiple actuation elements 44 with which microscope functions can also be switched are provided in the region around drive knob 42. The microscope functions are, for example, filter changing, aperture selection, revolving turret movement, etc.
[0038] Bridge 3 is attached to connecting element 50 a and 50 b of each microscope 30 a and 30 b. Analogously to FIG. 1, bridge 3 possesses a viewing port 4 for a user, and a tube 5 having a connection 6 for a camera (not depicted). Viewing port 4 for the user can be configured pivotably in order to maintain an ergonomic working position for the user. Both XYZ stages 8 a and 8 b are displaceable in the X direction, Y direction, and Z direction by way of several motors 16. Analogously to FIG. 1, first and second remote control device 18 a and 18 b are also associated with comparison optical system 1. These are each connected via a cable 19 to comparison optical system 1 or to PC 20. It is self-evident that the connection can assume any technical configuration, for example radio, infrared, etc. A display 22 is additionally associated with PC 20.
FIG. 3 is a detail view of control and [0039] adjustment apparatus 14 of FIG. 1, with which XYZ stages 8 a and 8 b of the comparison optical system are synchronously movable. Control and adjustment apparatus 14 encompasses a plurality of adjusting elements for comparison optical system 1. Provided on a front side 14 a of control and adjustment apparatus 14 is a switch 60, actuation of which causes a vertical displacement of column 10 (FIG. 1). This results in coarse focusing on the specimens that are present on XYZ stages 8 a and 8 b of comparison optical system 1 of FIG. 1. Directly above switch 60 is an on/off switch 61 for synchronous displacement of the two XYZ stages 8 a and 8 b. To the left of switch 60 is an X actuation element 62 a for displacing first XYZ stage 8 a in the X direction. To the right of switch 60 is an X actuation element 62 b for displacing second XYZ stage 8 b in the X direction. Provided above X actuation element 62 a is an adjustment element 63 a for an illumination system, with which the light intensity of an external light source (not depicted) can be modified. Similarly, above X actuation element 62 b is an adjustment element 63 b for an illumination system, with which the light intensity of an external light source (not depicted), whose light is directed onto second XYZ stage 8 b, can be modified.
In FIG. 3, only a first [0040] lateral surface 14 b of control and adjustment apparatus 14 is depicted visibly. On first lateral surface 14 b is a Y actuation element 64 b for displacing second XYZ stage 8 b in the Y direction. Also provided on first lateral surface 14 b is a Z fine displacement control 65 b for second XYZ stage 8 b in the Z direction. A Z fine displacement control 65 a for first XYZ stage 8 a is provided on second lateral surface 14 c.
Control and [0041] adjustment apparatus 14 furthermore possesses a top surface 14 d on which are mounted several actuation elements 70, 71, 72, 73, 74, 75, and 76 which are provided for modification of the image depiction. Actuation element 70 serves to generate a superimposed image, the image of the specimen on first XYZ stage 8 a being overlaid on the specimen on second XYZ stage 8 b. Actuation element 71 serves to generate a side-by-side depiction of the specimen on first XYZ stage 8 a next to the specimen on second XYZ stage 8 b. Actuation element 72 serves to generate a depiction of the image of the specimen on first XYZ stage 8 a. Actuation element 73 serves to generate a depiction of the image of the specimen on second XYZ stage 8 b. Actuation element 74 is used for manual aperture matching. Actuation element 75 is used for manual lateral shifting of the apertures. Actuation element 76 is used for secondary magnification of the specimens to be depicted. In a particular embodiment, a 1.5× magnification is provided.
An on/off [0042] switch 61 for synchronous displacement of the two XYZ stages 8 a and 8 b is configured in such a way that the functioning of the control elements is coupled, so that the previously independent X actuation elements 62 a and 62 b, Y actuation elements 64 a and 64 b, and Z fine displacement controls 65 a and 65 b for each individual XYZ stage 8 a and 8 b act synchronously on both XYZ stages 8 a and 8 b. Once the two XYZ stages 8 a and 8 b have been adjusted, the structures to be investigated are compared. These structures are often larger in terms of their dimensions than the region that is visible in the eyepiece or with the attached camera. To allow the entire specimen to be compared, both XYZ stages 8 a and 8 b must be shifted synchronously in the X direction, Y direction, and Z direction. It is thereby possible, using only one X actuation element or Y actuation element or the Z fine displacement control for each of the X, Y, and Z axes respectively, to displace the two XYZ stages 8 a and 8 b synchronously in order thereby to improve the evaluation of the specimens being investigated. In addition, the ergonomics of the entire comparison optical system 1 is considerably improved. A prerequisite for synchronization is motorization of the three axes of XYZ stages 8 a and 8 b. This applies both to macroscopes 2 a and 2 b or microscopes 30 a and 30 b that are connected by bridge 3.
In addition to control and [0043] adjustment apparatus 14 for macroscopes 2 a and 2 b, the latter also have associated with them a first remote control device and second remote control device 18 a and 18 b. Once macroscopes 2 a and 2 b or microscopes 30 a and 30 b have been adjusted in conventional fashion, the functioning of the actuation elements is coupled, by way of a button or a command from the PC (via RS232, USB, etc.), in such a way that upon actuation of any actuation element or the Z fine displacement control for a direction, both XYZ stages are moved synchronously. It is now possible, for example via X operating element 62 b of second XYZ stage 8 b and X operating element 62 a of first XYZ stage 8 a, to move both XYZ stages 8 a and 8 b synchronously in the X direction. The same applies to the axes in the Y and Z directions.
As with comparison optical system [0044] 1 in which macroscopes 2 a and 2 b are used, this function can be switched on by way of the built-in electronic system. When two microscopes 30 a and 30 b made up of two independently functioning stands are combined with a bridge 3, electronic synchronization of XYZ stages 8 a and 8 b is then accomplished via interfaces or PC 20. As depicted in FIG. 2, first microscope 30 a and second microscope 30 b have respectively associated with them a first remote control device 18 a and a second remote control device 18 b, which have actuation elements 24 for the X direction, Y direction, and Z direction of each XYZ stage 8 a and 8 b. As with macroscopes 2 a and 2 b, the synchronization makes it possible to control both XYZ stages 8 a and 8 b of microscopes 30 a and 30 b synchronously using only one remote control device 18 a or 18 b.

Claims

1. A comparison optical system comprising:

several image-acquiring optical subsystems

2. The comparison optical system as defined in claim 1, wherein each of the image-acquiring optical subsystems is a macroscope.

3. The comparison optical system as defined in claim 1, wherein each of the image-acquiring optical subsystems is a microscope.

4. The comparison optical system as defined in claim 1 wherein two image-acquiring optical subsystems are mechanically and optically coupled with the bridge.

5. The comparison optical system as defined in claim 1, wherein at least for the displacement of the XYZ stages in the X direction, Y direction, and Z direction, a motor is provided which receives the signals of the control unit and converts them into a corresponding rotation.

6. A comparison optical system comprising:

two macroscopes,

7. The comparison optical system as defined in claim 6, wherein the control unit is a control and adjustment apparatus that is associated with the macroscopes.

8. The comparison optical system as defined in claim 5, wherein the control unit is a control and adjustment apparatus that is associated with the macroscopes; and a first remote control device is respectively connected to the first macroscope; and a second remote control device is connected to the second macroscope.

9. The comparison optical system as defined in claim 8, wherein the control and adjustment apparatus possesses an X actuation element for displacement of the first XYZ stage and an X actuation element for displacement of the second XYZ stage, a Y actuation element for displacement of the first XYZ state and a Y actuation element for displacement of the second XYZ stage, and a Z fine displacement control for the first XYZ stage and a Z fine displacement control for the second XYZ stage.

10. The comparison optical system as defined in claim 9, wherein the control and adjustment apparatus encompasses an on/off switch for a synchronous displacement of the two XYZ stages which acts in such a way that when the on/off switch for synchronous displacement is switched on, both XYZ stages are movable synchronously regardless of the actuation of the X actuation element or X actuation element, the Y actuation element or Y actuation element, the Z fine displacement control or the Z fine displacement control.

11. The comparison optical system as defined in claim 9, wherein the first remote control device and the second remote control device encompass a plurality of actuation elements; and the actuation elements of the first remote control device and of the second remote control device are also synchronizable in pairs.

12. The comparison optical system as defined in claim 6, wherein the comparison optical system has associated with it a PC that, via an RS232 cable or a USB cable, supplies control signals to the comparison optical system and receives image data or settings data from the comparison optical system.

13. A comparison optical system comprising:

two microscopes,

14. The comparison optical system as defined in claim 13, wherein the control unit is a first remote control device that is associated with the first microscope; and a second remote control device is associated with the second microscope.

15. The comparison optical system as defined in claim 13, wherein the control unit is a control and adjustment apparatus which possesses an X actuation element for displacement of the first XYZ stage and an X actuation element for displacement of the second XYZ stage, a Y actuation element for displacement of the first XYZ state and a Y actuation element for displacement of the second XYZ stage, and a Z fine displacement control for the first XYZ stage and a Z fine displacement control for the second XYZ stage.

16. The comparison optical system as defined in claim 15, wherein the control and adjustment apparatus encompasses an on/off switch for a synchronous displacement of the two XYZ stages which acts in such a way that when the on/off switch for synchronous displacement is switched on, both XYZ stages are movable synchronously regardless of the actuation of the X actuation element or X actuation element, the Y actuation element or Y actuation element, the Z fine displacement control or the Z fine displacement control.

17. The comparison optical system as defined in claim 14, wherein the first remote control device and the second remote control device encompass a plurality of actuation elements; and the actuation elements of the first remote control device and of the second remote control device are also synchronizable in pairs.

18. The comparison optical system as defined in claim 13, wherein at least for the displacement of the XYZ stages in the X direction, Y direction, and Z direction, a motor is provided which receives the signals of the control unit and converts them into a corresponding rotation.

19. The comparison optical system as defined in claim 1, wherein the comparison optical system has associated with it a PC that, via an RS232 cable or a USB cable, supplies control signals to the comparison optical system and receives image data or settings data from the comparison optical system.

20. The comparison optical system as defined in claim 13, wherein the synchronization of the XYZ stages can be switched on and off by way of the PC (20).