WO1996028748B1

WO1996028748B1 - Optical system with wide measuring ranges

Info

Publication number: WO1996028748B1
Application number: PCT/EP1996/001115
Authority: WO
Filing date: 1996-03-14
Publication date: 1996-12-27
Anticipated expiration: 1997-09-14

Abstract

The invention concerns an optical system for use in spectrometry and/or endoscopy, in which at least one probe is exposed to directional radiation produced by a radiation source, the radiation emanating from the probe is led to a spectrometer, in particular a simultaneous spectrometer, and or to an imaging device. It is proposed that the optical system should be provided with at least one control device with a radiation inlet surface and a radiation outlet surface; the control device should be provided with control elements (24) held by a frame and capable of being displaced from a first position in such a way that the radiation energy transferred from the radiation inlet surface to the radiation outlet surface can be controlled while leaving the radiation outlet aperture substantially unchanged. In addition, or alternatively, the optical system is provided with at least wavelength selection unit which has at least one dispersion element element for spectral splitting of the radiation passing through at least one inlet slit and impinging on the dispersion element; and with at least one optical waveguide. The dispersion element and/or a focusing element focus the spectrally split radiation onto a focal surface and the optical waveguide receives a predetermined range of the spectrally split radiation in the focal surface.

Claims

AMENDED CLAIMS [received at the International Bureau on 18 November 1996 (18.11.96); original claims 1-51 replaced by new claims 1-46 (10 pages)]

1. Control device (20), in particular for spectroscopy, endoscopy and / or radiometry systems, with a radiation entrance and a radiation exit surface (21, 22), characterized

in that the control device (20) has control elements (24) held by a frame (23) which can be transferred from a first position to a second position such that the radiation transmitted by the radiation entrance surface (21) to the radiation exit surface (22) is substantially free constant aperture of the radiation is controllable,

the control elements (24) being connected to position change means (28, 29, 30) comprising wheels (28) and a spur gear (29),

wherein the wheels (28) are each connected to the circle segment (24) via the shaft (26) and have the contact surfaces (32) and the spur gear (29) is preferably rotatably mounted on the outside of the frame (23) and with the wheels (28) via a contact surface (31) is in contact.

2. Control device (20) according to claim 1, characterized in that the frame (23) defines an opening (25) into which the control elements (24) extend, 49

and that preferably the position of the control elements (24) is continuously variable.

3. Control device (20) according to claim 2, characterized in that the frame (23) of the control device

(20) has an annular cross-section parallel to the radiation entrance surface (21) and defines a circular opening (25).

4. Control device (20) according to any one of claims 1 to 3, characterized in that the control elements (24) are thin circular segments which are rotatably mounted in the frame (23) about its axis of symmetry.

5. Control device (20) according to claim 4, characterized in that the circular segments (24) each have a shaft (26) which are rotatably mounted in bearings (27), preferably plain bearings.

6. Control device (20) according to any one of claims 4 or 5, characterized in that at least three circular segments

(24) which, when parallel to the

Radiation inlet surface (21) are aligned, substantially the entire opening (25) of the control device

(20) cover.

7. Control device (20) according to claim 1 to 6, characterized in that the contact surface (31) of the spur gear

(29) is inclined so that the extension of the contact surface

(31) without offset at the intersection of the central axis of the

Spur gear (29) and the axes of symmetry of the circular segments

(24).

8. Control device (20) according to any one of claims 1 to 7, characterized in that the wheels (28) as bevel gears 50

are formed, wherein preferably the contact surfaces (32) of the bevel gears (28) corresponding to the contact surface (31) of the spur gear (29) are inclined.

9. Control device (20) according to any one of claims 1 to 8, characterized in that the contact surface (31) of the spur gear (29) and / or the contact surfaces (32) of the wheels (28) processed smoothly, in particular are ground.

10. Control device (20) according to any one of claims 1 to 9, characterized in that between the spur gear (29) and the wheels (28) a permanent magnetic closure is provided.

11. Control device (20) according to any one of claims 1 to 10, characterized in that the spur gear (29) via a worm drive (30) is movable.

12. Control device (20) according to claim 11, characterized in that the worm drive (30) is controllable by a computer.

13. Control device (20) according to any one of claims 1 to 12, characterized in that the control elements (24) are made of metal and preferably coated with a corrosion protection.

14. Control device (20) according to any one of claims 1 to 12, characterized in that the control elements (24) are made of a material which absorbs and / or reflects a predetermined part of the spectrum of the radiation.

15. wavelength selection device (10), in particular for spectroscopy, endoscopy and / or radiometry systems, 51

comprising at least one dispersion element (5) for the spectral splitting of a radiation falling through at least one entrance slit (3) onto the dispersion element (5), wherein the dispersion element (5) and / or a focusing element focuses the spectrally split radiation onto a focal surface (40), characterized,

in that at least one optical fiber bundle comprising a plurality of optical waveguides (42) is provided which accommodates a predetermined region of the spectrally split radiation in the focal surface (40), wherein the optical fiber bundle has a substantially uninterrupted end face and preferably the end face (43) of the optical fiber bundle to the focal surface (40) is adjusted.

16. wavelength selection device (10) according to claim 15, characterized in that in the focal surface (40) arranged ends of the light guide (42; 47) of the optical fiber bundle individually to the dispersion element (5) or against the center point of the respective real image of the entrance slit (3) are aligned.

17. wavelength selection device (10) according to claim 15 or 16, characterized in that a plurality of optical fibers

(42) are provided as ordered guided fiber optic bundles.

18. wavelength selection device (10) according to any one of claims 15 to 17, characterized in that the optical fiber bundle (47) the recorded radiation back to the dispersion element (5) leads, that at an exit slit of the wavelength selection device (10) radiation generated is, which has a predetermined spectral range.

19. wavelength selection device (10) according to claim 18, characterized in that the light guides of the optical fiber bundle (47) in the focal surface (40) received radiation back into the focal surface (40) and radiate towards the dispersion element (5).

20. wavelength selection device (10) according to claim 19, characterized in that the light guides of the optical fiber bundle (47) in the focal surface (40) received radiation back into the focal surface (40) lead, that the configuration of the receiving light receiving the radiation ends to the Configuration of the radiation-emitting optical fiber ends is mirror-symmetrical.

21. wavelength selection device (10) according to any one of claims 18 to 20, characterized in that in front of the radiation receiving end face of the light guide bundle (47) masks or panels are arranged, which are preferably displaceable.

22. wavelength selection device (10) according to any one of claims 18 to 21, characterized in that the radiation generated at the exit slit can be fed to an aperture converter, which has a coaxial, conical optical waveguide or mirror with a light entrance and a light exit opening, so that a substantially parallel beam with a predetermined spectral range can be generated.

23. wavelength selection device (10) according to any one of claims 15 to 22, characterized in that the 53

Light guide (42, 47) held in a socket and along the focal surface (40) is movable.

24. wavelength selection device (10) according to claim 23, characterized in that the contour of the guide track of the socket of the light guide chosen asymmetrically and preferably the guide track is provided with a coding.

25. wavelength selection device (10) according to any one of claims 15 to 24, characterized in that the diameter of the fibers of the light guide (42) is selected according to the computational resolution in the focal surface (40).

26. wavelength selection device (10) according to any one of claims 15 to 25, characterized in that a receiver unit (2) is provided and the light guide

(42) the received radiation to the receiver unit (2) leads.

27. wavelength selection device (10) according to claim 26, characterized in that the receiver unit (2) has at least one photodiode array, preferably a diode array (44).

28. wavelength selection device (10) according to claim 27, characterized in that the optical fiber bundle in a socket with an elongated planar surface, adapted to the geometry of the photodiode array ends.

29. wavelength selection device (10) according to any one of claims 27 or 28, characterized in that the optical fiber bundle and a plurality of diode rows

(44) and / or a surface arrangement (45) of photodiodes can be fed. 54

30. wavelength selection device (10) according to any one of claims 15 to 29, characterized in that two separate entrance gaps (3, 3 ') are provided so that in the focal surface (40) two separate spectra (S, S ¹ ) arise, and Light guide (42) are provided, each receiving a portion of the spectrally split radiation in the focal surface (40).

31. wavelength selection device (10) according to any one of claims 15 to 30, characterized in that the dispersion element (5) is a prism, preferably a Fery prism.

32. wavelength selection device (10) according to any one of claims 15 to 31, characterized in that the dispersion element (5) is a diffraction grating, preferably a concave grating.

33. wavelength selection device (10) according to claim 32, characterized in that the diffraction grating (5) sinusoidal furrows, rectangular furrows or sawtooth furrows.

34. wavelength selection device (10) according to claim 32 or 33, characterized in that the diffraction grating (5) is a holographic diffraction grating.

35. wavelength selection device (10) according to any one of claims 15 to 34, characterized in that between the entry slit (3) and the dispersion element (5) a control device according to one of claims 1 to 17 is arranged.

36. Optical system for spectrometry and / or endoscopy, in which at least one sample (9) by means of a 55

Radiation source (L) emanating outgoing radiation directed and irradiated from the sample (9) outgoing radiation to a receiver unit (2) and / or to an imaging device, characterized in that at least one control device (20) according to one of claims 1 to 14 or at least one wavelength selection device (10) according to one of claims 15 to 35 or both a control device (20) according to one of claims 1 to 14 and a wavelength selection device (10) according to one of claims 15 to 35 is provided.

37. System according to claim 36, characterized in that the radiation source (L) is a substantially punctiform radiation source of high luminance.

38. System according to one of claims 36 or 37, characterized in that the radiation source (L) by an aspherical mirror, preferably an ellipsoidal mirror, in an image (L ') is mapped.

39. System according to claim 38, characterized in that the control device (20) between the radiation source (L) and its image (L ') is arranged.

40. System according to one of claims 36 to 39, characterized in that for the optical energy transmission in the object space (8) between the radiation source (L) or its image (L ') and the sample (9) and / or between the sample ( 9) and the receiver unit (2) or the imaging unit at least one light guide is provided.

41. System according to one of claims 36 to 40, characterized in that for the optical energy transmission in the object space (8) between the radiation source (L) and the 56

Image (L ') and the sample (9) and / or between the sample (9) and the receiver unit (2) or the imaging unit an aperture converter (14, 15) is provided which comprises a coaxial, conical optical fiber or mirror with a Light entrance and a light exit opening, wherein the larger of the openings in each case the sample (9) faces.

42. System according to any one of claims 36 to 41, characterized in that the mirror (7) of the illumination device (6) and the dispersion element (5) of the wavelength selection device (10) have the same aperture.

43. Optical system for measuring at least a radiometric size of a radiation source, characterized in that

at least one receiver unit which can be irradiated with radiation from the radiation source and which has a calibrated operating point, in which a specific output value of the receiver unit is assigned to a specific value of the radiometric variable to be measured, and

between the radiation source and the receiver unit in the beam path a control device (20) according to one of claims 1 to 14 is provided,

so that by adjusting the control device (20) the output value of the receiver unit can be matched to the particular output value at the calibrated operating point of the receiver unit.

44. System according to claim 43, characterized in that between the radiation source and the receiver unit in 57

Beam path a wavelength selection device, in particular a wavelength selection device (10) according to one of claims 15 to 35 is provided.

45. System according to one of claims 43 or 44, characterized in that means are provided between the radiation source and the control device and / or between the control device and the receiver unit, which adapt the geometry of the radiation to the geometry of the control / receiver unit.

46. System according to any one of claims 43 to 45, characterized in that a reference radiation source and the switching means are provided so that selectively either the radiation of the radiation source to be measured or the radiation of the reference radiation source can be guided to the receiver unit.

MODIFIED SHEET (ARTICLE 19)