Method and system for processing scan-data from a confocal microscope

• US 6,423,960 B1
• Filed: 12/31/1999
• Issued: 07/23/2002
• Est. Priority Date: 12/31/1999
• Status: Expired due to Term

• Current Assignee: Leica Microsystems CMS GmbH (Danaher Corporation)
• Original Assignee: Leica Microsystems Heidelberg GmbH (Danaher Corporation)
• Inventors: Engelhardt, Johann, Widzgowski, Bernd
• Primary Examiner(s): Pyo, Kevin
• Assistant Examiner(s): Sohn, Seung C.
• Application Number:
  US09/476,589
• Time in Patent Office: 935 Days
• Field of Search: 250/214.R, 250/234, 250/235, 250/236, 250/216, 250/559.38, 250/214.DC, 250/214.L, 356/622, 341/155
• US Class Current: 250/214.00R
• CPC Class Codes: G02B 21/004 fixed arrays, e.g. switchable aperture arrays
• CPC Class Codes: G02B 21/0048 scanning mirrors, e.g. rotating or galvanomirrors, MEMS mirrors
• CPC Class Codes: G02B 21/0084 time-scale detection, e.g. strobed, ultra-fast, heterodyne detection

Abstract

The invention discloses a method and system for processing scan signals from a confocal microscope. The confocal microscope comprises an illumination source and a scanning device with a scanning mirror system. A control and processing unit is provided, which unit uses a plurality of programmable devices for the real time processing of digital signals. The control and processing unit has at least three input ports and one output port. A first detector generates analog signals corresponding to the light reflected from a specimen within the microscope and a second detector generates analog signals corresponding to the intensity of the light from the illumination source. In addition, a position signal of the scanning laser beam is provided to the control and processing unit. Analog-to-digital converters receive the analog signals, generate digital signals and provide the digital signals to the input ports of the control and processing unit.

Claims

1. A system for processing scan signals from a confocal microscope having a scanning device, the system comprising:

at least three different analog electrical signals generated by the confocal microscope, wherein a first analog electrical signal is proportional to the intensity of light reflected from a specimen, a second analog electrical signal is proportional to an illumination reference, and a third analog electrical signal is proportional to a positional signal generated by the scanning device;

a first analog-to-digital converter receiving a first analog electrical signal and converting it into a first digital signal;

a second analog-to-digital converter receiving a second analog electrical signal and converting it into a second digital signal;

a third analog-to-digital converter receiving a third analog electrical signal and converting it into a third digital signal; and

a control and processing unit using at least one programmable device for real time processing of the first, second and third digital signals received from the converters.

2. The system of claim 1, wherein at least one programmable device is a field programmable gate array.

3. The system of claim 1, wherein the control and processing unit comprises an address look up table to correct the position signal.

4. The system of claim 3, wherein the position signal generated by a scan in a “

+”

x-direction is different from the position signal generated by a scan in a “

−

”

x-direction.

5. The system of claim 1, wherein a first look up table carries out a log conversion of a first digital signal.

6. The system of claim 1, wherein a second look up table carries out a log conversion of a second digital signal.

7. The system of claim 1, wherein the control and processing unit comprises a calculating device and a line buffer.

8. A confocal microscope with a system for processing scan-signals comprising:

an illumination source directing a light beam onto a specimen;

a control and processing unit having a plurality of programmable devices, at least three input ports and one output port;

a first detector receiving the light reflected from the specimen;

a second detector receiving the light from the illumination source;

a scanning device generating a position signal; and

a first analog-to-digital converter receiving a signal generated by the first detector, a second analog-to-digital converter receiving a signal generated by the second detector, and a third analog-to-digital converter receiving the position signal generated by the scanning device, the first, the second and the third analog-to-digital converters outputting signals to the input ports of the control and processing unit.

9. The confocal microscope of claim 8, wherein the plurality of programmable devices are field programmable gate arrays.

10. The confocal microscope of claim 8, wherein the signal generated by the first detector is a first electrical signal corresponding to the intensity of the light reflected from the specimen, the signal generated by the second detector is a second electrical signal corresponding to an illumination reference, and the position signal is a third electrical signal corresponding to an actual position of the light beam on the specimen.

11. The confocal microscope of claim 10, wherein the control and processing unit comprises an address look up table to correct the position signal.

12. The confocal microscope of claim 11, wherein the scanning device comprises a scanning mirror system defining a positive scan path on a specimen surface in a “

+”

x-direction and a negative scan path in a “

−

”

x-direction.

13. The confocal microscope of claim 12, wherein the positive scan path differs from the negative scan path with respect to time.

14. The confocal microscope of claim 10, wherein a first look up table carries out a log conversion of the first electrical signal.

15. The confocal microscope of claim 10, wherein a second look up table carries out a log conversion of the second electrical signal.

16. The confocal microscope of claim 8, wherein the control and processing unit comprises a calculation device and a line buffer.

17. The confocal microscope of claim 10 further comprising a computer for receiving a correlated specific digital position signal and a specific digital detection signal, the computer having a display for providing an image of the specimen.

18. A method for processing scan signals from a confocal miscoscope, the method comprising:

generating at least three analog signals a, first signal corresponding to the light reflected from a specimen, a second signal corresponding to an illumination reference of the confocal microscope, and a position signal;

digitizing the first signal, the second signal and the position signal to provide digital signals comprising a first digital signal, a second digital signal and a digital;

position signal, respectively;

providing a control and processing unit receiving the digital signals, the control and processing unit having a plurality of programmable devices for real time processing of digital signals;

buffering the digital position signal in a line buffer of the control and processing unit;

correcting the first digital signal for intensity fluctuations by subtracting the second digital signal from the first digital signal and thereby generating a corrected digital detection signal; and

combining the corrected digital detection signal with the digital position signal to provide a combined signal.

19. The method of claim 18, wherein providing the control and processing unit having the plurality of programmable devices comprises providing the programmable devices that are field programmable gate arrays.

20. The method of claim 18 further comprising providing correction for the digital position signal by using an address look up table in the control and processing unit.

21. The method of claim 20, wherein providing correction of the digital position signal is accomplished by correcting a scan in a“

+”

x-direction and correcting a scan in a “

−

”

x-direction.

22. The method of claim 18, wherein a first look up table carries out a log conversion of the first digital signal.

23. The method of claim 18, wherein a second look up table carries out a log conversion of the second digital signal.

24. The method of claim 18 further comprising feeding the combined signal to a computer and displaying an image of the specimen.