SPECTROMETER WITH LED ARRAY

• US 20100208261A1
• Filed: 10/08/2008
• Published: 08/19/2010
• Est. Priority Date: 10/11/2007
• Status: Abandoned Application

• Current Assignee: BASF SE
• Original Assignee: BASF SE
• Inventors: Thiel, Erwin, Sens, Ruediger, Ahlers, Wolfgang, Vamvakaris, Christos
• Application Number:
  US12/680,847
• Publication Number:
  US 20100208261A1
• Time in Patent Office: Days
• US Class Current: 356/326
• CPC Class Codes: G01J 2003/104 Monochromatic plural sources
• CPC Class Codes: G01J 3/0272 Handheld
• CPC Class Codes: G01J 3/10 Arrangements of light sources specially adapted for spectrometry or colorimetry
• CPC Class Codes: G01J 3/42 Absorption spectrometry; Double beam spectrometry; Flicker spectrometry; Reflection spectrometry beam switching arrangements G01J3/08
• CPC Class Codes: G01N 2021/0143 with internal and external computer
• CPC Class Codes: G01N 2021/0389 Windows
• CPC Class Codes: G01N 2021/6419 Excitation at two or more wavelengths
• CPC Class Codes: G01N 2021/6421 Measuring at two or more wavelengths
• CPC Class Codes: G01N 2021/6491 Measuring fluorescence and transmission; Correcting inner filter effect
• CPC Class Codes: G01N 21/0303 Optical path conditioning in cuvettes, e.g. windows; adapted optical elements or systems; path modifying or adjustment G01N21/031 - G01N21/15 take precedence
• CPC Class Codes: G01N 21/255 Details, e.g. use of specially adapted sources, lighting or optical systems
• CPC Class Codes: G01N 21/55 Specular reflectivity
• CPC Class Codes: G01N 21/643 non-biological material
• CPC Class Codes: G01N 21/645 Specially adapted constructive features of fluorimeters
• CPC Class Codes: G01N 2201/0221 Portable; cableless; compact; hand-held
• CPC Class Codes: G01N 2201/0222 Pocket size
• CPC Class Codes: G01N 2201/0624 Compensating variation in output of LED source
• CPC Class Codes: G01N 2201/0625 Modulated LED
• CPC Class Codes: G01N 2201/0627 Use of several LED's for spectral resolution
• CPC Class Codes: G01N 33/28 Oils , i.e. hydrocarbon liquidsgaseous fuels G01N33/225; edible oils or edible fats G01N33/03

Abstract

A device (110) for determining at least one optical property of a sample (112) is proposed. The device (110) comprises a tuneable excitation light source (114; 410) for applying excitation light (122) to the sample (112). The device (110) furthermore comprises a detector (128, 130; 312) for detecting detection light (132, 136; 314) emerging from the sample (112). The excitation light source (114; 410) comprises a light-emitting diode array (114), which is configured at least partly as a monolithic light-emitting diode array (114). The monolithic light-emitting diode array (114) comprises at least three light-emitting diodes (426) each having a different emission spectrum.

Claims

1-36. -36. (canceled)

37. A device for determining at least one optical property of a sample, wherein the device comprises a tuneable excitation light source for applying excitation light to the sample, wherein the device furthermore comprises a detector for detecting detection light emerging from the sample, wherein the excitation light source comprises a light-emitting diode array, wherein the light-emitting diode array is configured at least partly as a monolithic light-emitting diode array, wherein the monolithic light-emitting diode array comprises at least three light-emitting diodes each having different emission spectrums, wherein the light-emitting diodes of the light-emitting diode array lie so close together that if all the light-emitting diodes of the light-emitting diode array are switched on, essentially a mixed light beam arises, wherein the individual emissions of the light-emitting diodes of the light-emitting diode array are essentially combined to form a common beam of excitation light.

38. The device according to claim 37, wherein the light-emitting diode have an average spacing which is less than one millimetre.

39. The device according to claim 37, wherein the light-emitting diode array comprises at least one of the following light-emitting diode arrays:

an inorganic monolithic light-emitting diode array having an inorganic semiconductor chip;

an organic monolithic light-emitting diode array having a thin-film transistor circuit integrated on a carrier of the light-emitting diode array.

40. The device according to claim 37, wherein the light-emitting diode array comprises at least ten light-emitting diodes.

41. The device according to claim 37, furthermore comprising a temperature-regulating device, wherein the temperature-regulating device is designed to regulate the temperature of the light-emitting diode array.

42. The device according to claim 41, wherein the temperature-regulating device furthermore comprises a regulation device.

43. The device according to claim 37, wherein the light-emitting diodes of the light-emitting diode array each have a spectral width, wherein the spectral width does not exceed a value of 30 nm.

44. The device according to claim 37, wherein the light-emitting diodes of the light-emitting diode array cover a spectral range of 450 nm to 850 nm.

45. The device according to claim 37, wherein the detector comprises a detector array having at least two individual detectors, wherein the detector array comprises a monolithic photodiode array.

46. The device according to claim 37, wherein the detector has at least one luminescence light detector arranged non-collinearly with the excitation light.

47. The device according to claim 37, wherein the detector has at least one transmission light detector arranged collinearly with the excitation light.

48. The device according to claim 37, wherein the detector has at least one reflection light detector for detecting reflection light reflected from the sample.

49. The device according to claim 37, furthermore having a control device, wherein the control device is designed to generate excitation light having predetermined spectral properties by driving the individual light-emitting diodes of the light-emitting diode array.

50. The device according to claim 49, wherein the control device comprises a multiplexing device, wherein the multiplexing device is designed to modulate at least two of the light-emitting diodes of the light-emitting diode array with different modulation frequencies.

51. The device according to claim 50, wherein the control device furthermore has a demodulation device, wherein the demodulation device is designed to demodulate detection light phase-sensitively and/or frequency-sensitively and to assign it in each case to one of the modulated light-emitting diodes.

52. The device according to claim 51, wherein the device is designed to record an excitation spectrum of the sample, wherein a plurality of light-emitting diodes of the light-emitting diode array are operated simultaneously, wherein the excitation light contains differently modulated portions of the individual light-emitting diodes, wherein the detection light is demodulated and assigned to the individual light-emitting diodes, and wherein a corresponding excitation spectrum is generated.

53. The device according to claim 37, furthermore comprising a cuvette for receiving a liquid sample, wherein the cuvette has at least partly a circular cross section.

54. The device according to claim 37, wherein the device is configured as a two-channel spectrometer, wherein the device is designed to simultaneously pick up at least one optical property of the sample and a reference beam.

55. The device according to claim 54, wherein at least one optical property of a reference sample is determined.

56. The device according to claim 37, wherein the device is configured as a mobile handheld unit.

57. The device according to claim 56, wherein the mobile handheld unit furthermore has an interface for connecting the mobile handheld unit to a mobile data transmission unit or a computer.

58. A method for checking whether a product is a branded product or a counterfeit of a branded product, wherein the branded product has at least one characteristic optical property, wherein a device according to claim 37 is used, wherein the device is used to test whether the product has the characteristic optical property.

59. A method according to claim 58, wherein the branded product comprises a mineral oil product.