Search

EP-4735867-A1 - CONICAL DIFFUSE REFLECTOR FOR HOMOGENEOUS ILLUMINATION

EP4735867A1EP 4735867 A1EP4735867 A1EP 4735867A1EP-4735867-A1

Abstract

The invention relates to an optical unit (114) for a spectrometer device (112) for analyzing at least one sample (116). The optical unit (114) comprises a plurality of light emitting elements (120) configured for emitting light for illuminating the sample (116); a conical light guide (122) comprising at least one scattering element (124) arranged between opposing, differently sized openings (126) of the conical light guide (122), the conical light guide (122) being configured for scattering at least part of the light emitted by the light emitting elements (120); at least one reflector (128) configured for reflecting at least part of the light scattered by the light guide (122) in a direction toward the sample (116), wherein the light emitting elements (120) and the reflector (128) are arranged on a side of the conical light guide (122) having the bigger opening (130), wherein the sample (116) is placeable on a side of the conical light guide (122) having the smaller opening (132). Further disclosed are a spectrometer device (112), a spectrometer system (110) and various uses of the spectrometer device (112).

Inventors

  • NAGLER, Benjamin
  • KLEIN, ALEXANDER
  • HORSAK, Andre
  • SIEBRECHT, PHILIPP

Assignees

  • trinamiX GmbH

Dates

Publication Date
20260506
Application Date
20240627

Claims (15)

  1. 1 . An optical unit (114) for a spectrometer device (112) for analyzing at least one sample (116), comprising a plurality of light emitting elements (120) configured for emitting light for illuminating the sample (116); a conical light guide (122) comprising at least one scattering element (124) arranged between opposing, differently sized openings (126) of the conical light guide (122), the conical light guide (122) being configured for scattering at least part of the light emitted by the light emitting elements (120); at least one reflector (128) configured for reflecting at least part of the light scattered by the light guide (122) in a direction toward the sample (116), wherein the light emitting elements (120) and the reflector (128) are arranged on a side of the conical light guide (122) having the bigger opening (130), wherein the sample (116) is placeable on a side of the conical light guide (122) having the smaller opening (132).
  2. 2. The optical unit (114) according to the preceding claim, wherein the scattering element (124) comprises an uneven, irregularly patterned, reflective surface.
  3. 3. The optical unit (114) according to the preceding claim, wherein the surface comprises a diffuser configured for total reflection.
  4. 4. The optical unit (114) according to any one of the preceding claims, wherein the scattering element (124) comprises at least one material selected from the group consisting of: a metal and/or metallic material; a glass; a plastic material; a ceramic.
  5. 5. The optical unit (114) according to any one of the preceding claims, wherein the conical light guide (122) is hollow or is at least partially filled with at least one optically transparent material.
  6. 6. The optical unit (114) according to any one of the preceding claims, wherein an area ai of the smaller opening (132) is smaller than an area a2 of the bigger opening (130) of the conical light guide (122) by at least a factor of 1 .1 , such that a2 1.1 ai.
  7. 7. The optical unit (114) according to any one of the preceding claims, wherein the light emitting elements (120) are arranged at least partially intruding into the bigger opening (130) of the conical light guide (122).
  8. 8. The optical unit (114) according to any one of the preceding claims, wherein the light emitting elements (120) are arranged around a center point and/or a central light axis of the optical unit (114), wherein the light emitting elements are arranged at a distance from the central light axis of at least half of a diameter of the smaller opening of the conical light guide.
  9. 9. The optical unit (114) according to any one of the preceding claims, wherein at least one of the light emitting elements (120) is selected from the group consisting of: a thermal radiator; a heat source; a laser; a light emitting diode (LED); a miniaturized thin-film emitter; a structured light source; a gas discharge lamp.
  10. 10. A spectrometer device (112) for analyzing at least one sample (116), comprising: an optical unit (114) according to any one of the preceding claims; at least one optical detector (118) configured for generating at least one detector signal according to the illumination of the optical detector (118) by at least a portion of the light emitted by the light emitting element (120) and reflected by the sample (116); wherein the optical unit (114) is arranged between the optical detector (118) and the sample (116).
  11. 11. A spectrometer system (110) for analyzing at least one sample (116), the spectrometer system (110) comprising at least one sample (116) and at least one spectrometer device (112) according to any one of the preceding claims referring to a spectrometer device (112), wherein the sample (116) and the spectrometer device (112) are arranged and configured for essentially homogeneously illuminating at least one measurement area (146) of the sample (116) by the light emitted by the light emitting elements (120).
  12. 12. The spectrometer system (110) according to the preceding claim, wherein the sample (116), at least in the at least one measurement area (146), comprises at least one inhomogeneous characteristic.
  13. 13. The spectrometer system (110) according to the preceding claim, wherein a degree of variance of the at least one characteristic in the measurement area (146) of the sample (116) is at least 10 %.
  14. 14. The spectrometer system (110) according to any one of the two preceding claims, wherein the characteristic of the sample (116) is selected from the group consisting of: a color, a shape, a particle size, a mass distribution, a density, a material, a texture, a temperature.
  15. 15. A use of a spectrometer device (112) according to any one of the preceding claims referring to a spectrometer device (112) in one or more of: an infrared detection application; a spectroscopy application; an exhaust gas monitoring application; a combustion process monitoring application; a pollution monitoring application; an industrial process monitoring application; a mixing or blending process monitoring; a chemical process monitoring application; a food processing process monitoring application; a food preparation process mon- itoring; a water quality monitoring application; an air quality monitoring application; a quality control application; a temperature control application; a motion control application; an exhaust control application; a gas sensing application; a gas analytics application; a motion sensing application; a chemical sensing application; a mobile application; a medical application; a mobile spectroscopy application; a food analysis application; an agricultural application, in particular characterization of soil, silage, feed, crop or produce, monitoring plant health; a plastics identification and/or recycling application.

Description

Conical Diffuse Reflector for Homogeneous Illumination Technical Field The invention relates to an optical unit for a spectrometer device for analyzing a sample, to a spectrometer device, to a spectrometer system as well as to various uses of the spectrometer device. Such devices and systems can, in general, be used for investigation or monitoring purposes, in particular, in the infrared (IR) spectral region, especially in the near-infrared (NIR) and the mid infrared (MidlR) spectral regions, and for a detection of heat, flames, fire, or smoke. However, further kinds of applications are possible. Background art Various optical units, spectrometer devices and systems for investigations in the IR spectral region, in particular in the NIR and MidlR spectral regions, are known. Especially, optical units and spectrometer devices that comprise a combination of parabolic mirrors and incandescent lamps have been proposed. Therein, the incandescent lamps are commonly used to cover the required wavelength range with their broad spectrum formed as a black-body radiator by Planck’s law. These setups however generally require precise component placement and narrow manufacturing tolerances, since even small deviations tend to trigger high spatial dependency of the illumination of the sample. The resulting high alignment efforts usually render large- scale production uneconomical. One generally accepted approach for overcoming this issue is performing multiple measurements at different locations. Specifically, multiple measurements are typically performed, thereby converging in an averaging prediction about a material parameter to be measured. However, performing multiple measurements is cumbersome and costly. Problem to be solved It is therefore desirable to provide an optical unit, a spectrometer device and a spectrometer system that may, in particular, be suited for investigations in the IR spectral region, especially in the NIR and MidlR spectral regions, and which at least substantially avoid the disadvantages of known devices and systems of this type. In particular, it would be desirous to provide an improved, simple, cost-efficient and still reliable optical unit for a spectrometer device. Summary This problem is addressed by an optical unit, a spectrometer device, a spectrometer system and a use of a spectrometer device with the features of the independent claims. Advantageous embodiments which might be realized in an isolated fashion or in any arbitrary combinations are listed in the dependent claims as well as throughout the specification. In a first aspect, the present invention relates to an optical unit for a spectrometer device for analyzing a sample. The optical unit comprises: a plurality of light emitting elements, i.e. at least two light emitting elements, configured for emitting light for illuminating the sample; a conical light guide, e.g. configured for homogenizing the light emitted by the light emitting elements, comprising at least one scattering element arranged between opposing, differently sized openings of the conical light guide, the conical light guide, specifically by its scattering element, being configured for scattering, i.e. diffusely reflecting, at least part of the light emitted by the light emitting elements, i.e. the part of the emitted light illuminating the scattering element; at least one reflector configured for reflecting at least part of the light scattered by the light guide in a direction toward the sample, wherein the light emitting elements and the reflector are arranged on a side of the conical light guide having the bigger opening, wherein the sample is placeable on a side of the conical light guide having the smaller opening. The term “optical unit” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The time specifically may refer, without limitation, a part of a spectrometer device configured for guiding the electromagnetic radiation, i.e. light, through and/or within the spectrometer device, such as for controlling a light path, to and from the sample. The term “spectrometer device” as used herein is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not to be limited to a special or customized meaning. The term specifically may refer, without limitation, to an apparatus that is by guiding electromagnetic radiation to and from at least one sample, e.g. by its optical unit, capable of determining spectral information of the sample, such as information on at least one spectrum of the at least one sample, by recording at least one measured value for at least one signal intensity, i.e. an intensity of electromagnetic radiation, such as a light intensity. The signal may specifically be generated, preferably as an electrical signal, by a detector of the spectrometer device wit