Spectrometer device and corresponding method for operating a spectrometer device

Abstract

The invention provides a spectrometer device (10), comprising: at least one light source (11) for irradiating a sample (18) with light; an optical detection device (12) for detecting light scattered by the sample (18); at least one optical filter device (13), the optical filter device being arranged in front of and / or behind the sample (18); a contact sensor device (15, 16) for determining contact (19) between the sample and the spectrometer device (10) and for outputting a corresponding output signal; a control device (17) for controlling the light source (11) and the detection device (12) in response to the output signal, wherein the control device (17) is constructed such that when the output signal indicates contact (19) between the sample and the spectrometer device (10), the control device changes at least one operating parameter of the light source (11) and the detection device (12). The invention also provides a method for operating a spectrometer device (10).

Description

Technical Field

[0001] The invention relates to a spectrometer device and a corresponding method for operating a spectrometer device. Background Art

[0002] Spectrometers are indispensable in many scientific fields for analyzing any type of sample. In recent years, there has been a trend toward miniaturization of spectrometers, because this allows them to be used more flexibly. Spectrometers usually consist of a light source, a spectral filter and a detector. In this case, the filter is placed between the light source and the sample or between the sample and the detector. Thus, U.S. Patent Publication US7061619B2 describes a miniaturized spectrometer.

[0003] With the popularity of mobile phones and smartphones, the idea of ​​integrating spectrometers into handheld devices was born. This means that spectrometers can also be used on the road and that the detected spectra can be stored freely and openly for each user, for example in the cloud. In this way, the spectra can be used for comparative analysis, for example to determine the ripeness of fruit. In a further step, intelligent algorithms can use the stored spectra, for example to implement machine vision in the field of robotics. However, these applications presuppose that the spectra are detected without errors, which is usually only possible for trained personnel. However, new applications also require untrained personnel to carry out the detection.

[0004] In order to improve the reliability of the detected spectrum and avoid sources of error, contact between the spectrometer and the sample may be advantageous. For example, US patent publication US 6045502 A describes a spectrometer that is in contact with the sample via a refractive index adapter. This device, which is usually in the form of a gel, is used to avoid undesirable reflections that could distort the spectrum.

[0005] Figure 3a )-3b) is a schematic diagram of a typical spectrometer apparatus with a sample.

[0006] so, Figure 3a ) comprises a sample 31, which is placed in front of a detection device 32, an optical filtering device 33 and a light source 34. In this example, the optical filtering device 33 is placed directly in front of the light source 34, so that only filtered, usually narrow-band light radiation always strikes the sample 31. Then, part of the radiation reflected by the sample and possibly exciting it strikes the detection device 32, which can then detect the spectrum of the sample.

[0007] As a structural variant, Figure 3b) shows a spectrometer device 30 ', in which the optical filtering device 33 is not placed in front of the light source 34, but in front of the detection device 32. In this way, the full spectrum of the usually broadband light source simultaneously impinges on the sample 31, and the radiation reflected by the sample 31 and possibly excited is filtered before it impinges on the detection device 32. Summary of the invention

[0008] The invention provides a spectrometer device according to the invention and a corresponding method for operating a spectrometer device. Preferred embodiments are the subject matter of various specific embodiments.

[0009] Advantages of the present invention

[0010] In order to simplify the operation, it is desirable to omit the refractive index adapter for making contact. In addition, the miniaturized spectrometer should be designed so that detection parameters such as the measurement duration or the illumination intensity can be adapted depending on the contact situation. Alternatively, the spectrum should be provided with at least a mark, from which it can be concluded whether the spectrum was detected when there was contact between the sample and the spectrometer.

[0011] The idea on which the invention is based is to provide a spectrometer device with contact detection. Depending on whether there is contact between the sample and the spectrometer, the operating parameters that take into account the presence of contact can be adapted. In this way, when there is contact, the scattered light is usually shielded, which leads to a higher signal-to-noise ratio. In this way, in some cases, a shortened measurement time or a reduced illumination intensity is sufficient to detect a reliable spectrum. On the contrary, when there is no contact, these parameters should be increased in some cases.

[0012] According to a preferred extension, the control device is constructed so that the detection of the spectrum is activated only when there is contact between the spectrometer device and the sample. This extension brings the advantage of higher reliability of the detected spectrum. In this way, the detected spectrum can be detected more easily without error when there is contact, because scattered light and other environmental influences that may distort the measurement data are shielded when the sample is opaque. In this way, the spectrum can also be detected with high reliability for untrained users.

[0013] According to another preferred extension, the control device is constructed so that when there is contact between the spectrometer device and the sample, the detection of the spectrum is activated with a higher or lower illumination intensity than when there is no contact. Usually, the presence of contact is accompanied by shielding, which prevents scattered light from entering the spectrometer device when the sample is opaque, and also prevents the light emitted by the light source from being transmitted outward. Thus, the presence of contact allows the limit value specified by the safety regulations for the illumination intensity to be exceeded, which would otherwise be dangerous to the human eye. As the illumination intensity increases, the signal-to-noise ratio and the accuracy of the spectrum detected thereby can be improved. Lower illumination intensity brings the advantage of saving energy when the spectrometer is running.

[0014] According to another preferred extension, the control device is constructed so that when there is no contact between the spectrometer device and the sample, a prompt signal can be output to the user. This prompt signal can be used to request the user to reduce the lighting intensity when there is no contact, because the lighting intensity is higher than the allowed limit value. The user also has the opportunity to correct the placement of the sample relative to the spectrometer device in order to establish contact. This ensures that the user does not make mistakes when there is no contact, which is what the user really wants to do when there is contact.

[0015] According to another preferred embodiment, the control device is designed so that when there is contact between the spectrometer device and the sample, a label representing the contact can be assigned to the spectrum. The label provides information about the reliability of the detected spectrum, because it is assumed that the spectrum detected when there is contact has a higher reliability than the spectrum detected when there is no contact. Thus, this embodiment makes it possible, for example, to distinguish spectra in a database according to their reliability, which is important for comparative analysis with other spectra of similar samples.

[0016] According to another preferred extension, the operating parameters include a measurement duration and / or a scan time. With this extension, the measurement duration and / or the scan time can be adapted according to the output signal to ensure a sufficiently large signal-to-noise ratio. Thus, when there is contact between the sample and the spectrometer device, a shorter measurement duration and / or scan time is usually required, thereby saving time for detecting the spectrum in general.

[0017] According to another preferred extension, the spectrometer device is integrated into a mobile phone, a smartphone or other handheld device. This integration makes the use of the spectrometer device significantly easier. In this way, it can also be used on the way, for example in places that are difficult to reach. By this, the sample no longer has to be brought only to the spectrometer device, but the spectrometer device can also be brought to the sample. For example, this allows the spectrum of the plants to be detected in the field in their original position. This makes it possible, for example, to determine the maturity of the fruit before picking it.

[0018] According to another preferred extension, the contact sensor device includes a proximity switch, an ambient light sensor, an inertial sensor and / or a camera. The use of one or more of the listed devices improves the reliability of contact recognition and reduces the probability of misunderstanding. Here, the proximity switch can be an inductive proximity switch, a capacitive proximity switch, a magnetic proximity switch (for example, a reed switch or a reed contact or also a Hall sensor), an optical proximity switch, a grating or an ultrasonic proximity switch or a micro switch, which closes the electrical contact when surface contact occurs. The ambient light sensor can infer dimness when the light source is cut off or modulated, thereby identifying contact. In the case of an inertial sensor, the following state can be inferred by analyzing the signal of, for example, an acceleration spectrum, namely whether there is contact between the spectrometer device and the sample. Using a camera, contact can be inferred by direct observation.

[0019] According to another preferred extension scheme, the light source has an incandescent lamp, a thermal emitter, an LED, an LED with a phosphor light source, a white light laser, a quantum dot light source, a white light source, a gas discharge lamp or other broadband light source. This extension scheme enables detection of the spectrum in a wide wavelength or frequency range. Due to the larger range, more information can usually be extracted from the sample.

[0020] According to another preferred embodiment, the filter device has a Fabry-Perot interferometer or a grating device. With this device, the optical radiation can be filtered effectively and spectrally modulated, whereby the spectrum can be detected with high spectral resolution. As a result, more information can usually be extracted from the sample.

[0021] According to another preferred embodiment, the contact sensor device is arranged separately from the spectrometer device. In this embodiment, the contact sensor device is not connected to the spectrometer device, but can be installed in a separate part of a superordinate device, such as a smart phone. This makes it possible to use components already present in the device for the contact sensor device.

[0022] According to another preferred extension, the detection of the spectrum is activated only when there is contact between the spectrometer device and the sample. This extension also brings the advantage of higher reliability of the detected spectrum. In this way, the detected spectrum can be detected more easily without error when there is contact, because scattered light and other environmental influences that may distort the measurement data are shielded. In this way, the spectrum can also be detected with high reliability for untrained users.

[0023] According to another preferred embodiment, the detection of the spectrum is activated with a higher illumination intensity when there is contact between the spectrometer device and the sample than when there is no contact. Here, the presence of contact with the opaque sample and the shielding associated therewith also allow the limit values ​​prescribed by safety regulations for the illumination intensity to be exceeded, which would otherwise be dangerous to the human eye. With increasing illumination intensity, the signal-to-noise ratio and thereby the accuracy of the detected spectrum can be improved.

[0024] According to another preferred extension, a prompt signal is output to the user when there is no contact between the spectrometer device and the sample. This prompt signal can be used to request the user to reduce the lighting intensity when there is no contact, because the lighting intensity is higher than the allowed limit value. The user also has the opportunity to correct the placement of the sample relative to the spectrometer device in order to re-establish contact. This ensures that the user does not make mistakes in detecting the spectrum when there is no contact, which is what the user really wants to do when there is contact. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Other features and advantages of the present invention will be explained below based on embodiments with reference to the accompanying drawings.

[0026] in:

[0027] Figure 1 ) shows a schematic diagram of a spectrometer device with a sample according to a first embodiment of the present invention;

[0028] Figure 2 ) shows a schematic diagram of a method for operating a spectrometer device according to a first embodiment of the present invention; and

[0029] Figure 3a )-3b) shows a schematic diagram of a typical spectrometer apparatus with a sample. DETAILED DESCRIPTION

[0030] In the figures, identical reference signs denote identical or functionally identical elements.

[0031] Figure 1 ) is a schematic diagram of a spectrometer device with a sample according to a first embodiment of the present invention.

[0032] exist Figure 1), the spectrometer device 10 comprises: two light sources 11; a detection device 12, which includes an optical filtering device 13 and a photodetector 14; a contact sensing device 15, 16, which includes an ambient light sensor 15 and an inertial sensor 16; and a control device 17, which is connected to the contact sensing device 15, 16, the detection device 12 and the light source 11. Here, the sample 18 is in contact 19 with the spectrometer device 10, which means that the sample 18 is in physical contact with the spectrometer device 10, or the sample is placed very close to the spectrometer device.

[0033] The two light sources 11 shown here are angled so that the illumination field overlaps, for example, a window (not shown) of the spectrometer device 10, thereby illuminating the sample. The radiation reflected by the sample and possibly excited is partly incident, preferably via an optical system, into a filter device 13 of the detection device. Here, the filter device is designed so that it can filter the radiation in a way that it can be dimmed in a specified wavelength range, so that only a narrow band range always strikes the photodetector 14. Finally, the spectrum in the specified wavelength range is detected by dimming.

[0034] The field of view of the ambient light sensor 15 overlaps with the illumination field of the light source 11 and the window of the spectrometer device 10. Thus, when there is contact 19 with an opaque sample 18 and the light source 11 is switched off, practically no ambient light enters the spectrometer device 10 anymore, so that the ambient light sensor 15 detects darkness in the case of an opaque sample 18. The inertial sensor 16 assists the measurement in that it provides an acceleration spectrum which can provide further information about the contact 19. Thus, the acceleration spectrum can have smaller high-frequency swings when there is a contact 19, since the inertia is then increased due to the combined weight of the spectrometer device 10 and the sample 18. These data can be used to unambiguously determine the contact 19, especially in the case of transparent samples.

[0035] The control device 17 obtains data from the contact sensor devices 15 and 16 and controls the light source 11 and the detection device 12 accordingly and specifies the operating parameters of these light sources and the detection device. Usually, when there is contact 19, the control device 17 increases the lighting intensity of the light source 11. On the contrary, when there is no contact, the lighting intensity should be reduced to below the limit value specified by safety regulations. The control device 17 usually controls the detection device 12 so that the measurement duration and / or scanning time is less when there is contact than when there is no contact. However, this depends on the specific sample, for example, whether the specific sample is at least partially transparent. It is also provided that these operating parameters are automatically specified or can be manipulated by the user.

[0036] Figure 2) is a schematic diagram of a method for operating a spectrometer device according to a first embodiment of the present invention.

[0037] The method 20 for operating the spectrometer device 10 begins with the classification of the sample 21. The sample is now placed 22 relative to the spectrometer device 10. It is then determined 23 by the contact sensor device 15, 16 whether there is contact 19 between the spectrometer device 10 and the sample 18. When there is contact 19, the illumination intensity of at least one light source is increased or maximized 24. Furthermore, before the spectrum of the sample 18 is detected 26 by the detection device 12, the remaining measurement parameters such as the measurement duration and / or the scanning time are adapted 25. Finally, the detected spectrum is marked 27, which can contain the type of sample and / or information about whether the sample was detected when there was contact.

[0038] In the case of classification 21 of a sample 18, a contact threshold value may be adapted 28, which contact threshold value is used for the determination 23 of a contact 19. Thus, for example, an inertial sensor may have more difficulty identifying a contact 19 in the case of a soft sample material such as a textile than in the case of a hard and heavy sample 18. Furthermore, in the step of determining 23 a contact 19 and ascertaining the absence of a contact 19, a user may be requested 29 to reposition the spectrometer device relative to the sample.

[0039] Although the invention has been described with reference to preferred embodiments, the invention is not limited to these embodiments. In particular, the materials and topologies mentioned are merely exemplary and are not limited to the examples described.

[0040] In particular, other inclination directions, angles, geometries, etc. can be selected for the individual elements. The elements and components can also be arranged in other sensible ways.

Claims

1. A spectrometer device (10), comprising: at least one light source (11) for irradiating the sample (18) with light; an optical detection device (12) for detecting (26) light scattered by the sample (18); at least one optical filtering device (13), which is arranged in front of and / or behind the sample (18); contact sensing means (15, 16) for determining contact (19) between the sample (18) and the spectrometer device (10) and for outputting a corresponding output signal; a control device (17) for controlling the light source (11) and the detection device (12) in response to the output signal, The control device (17) is designed so that when the output signal indicates contact (19) between the sample (18) and the spectrometer device (10), the control device changes at least one operating parameter of the light source (11) and the detection device (12).

2. The spectrometer device according to claim 1, wherein the control device (17) is designed such that the detection of the spectrum is activated only when there is contact (19) between the spectrometer device (10) and the sample (18).

3. The spectrometer device according to claim 1, wherein the control device (17) is designed to activate the detection of the spectrum when there is contact (19) between the spectrometer device (10) and the sample (18) with a higher or lower illumination intensity than when there is no contact.

4. The spectrometer device according to any one of the preceding claims, wherein the control device (17) is designed to output a prompt signal to a user when there is no contact between the spectrometer device (10) and the sample (18).

5. The spectrometer device according to any one of claims 1 to 3, wherein the control device (17) is designed so that when contact exists between the spectrometer device (10) and the sample (18), a label representing the contact can be assigned to the spectrum. 6 . The spectrometer device according to claim 1 , wherein the operating parameters include a measurement duration and / or a scan time.

7. The spectrometer device according to any one of claims 1 to 3, wherein the spectrometer device (10) is integrated into a mobile phone, a smart phone or other handheld device.

8. The spectrometer device according to any one of claims 1 to 3, wherein the contact sensing device (15, 16) comprises a proximity switch, an ambient light sensor, an inertial sensor and / or a camera.

9. The spectrometer device according to any one of claims 1 to 3, wherein the light source (11) comprises a thermal emitter, an LED, a white light laser, a quantum dot light source, a white light source, a gas discharge lamp or another broadband light source.

10. The spectrometer apparatus of claim 9, wherein the thermal emitter comprises an incandescent lamp, and wherein the LED comprises an LED with a phosphor light source.

11. The spectrometer device according to claim 1, wherein the filter device (13) comprises a Fabry-Perot interferometer or a grating device.

12. The spectrometer device according to any one of claims 1 to 3, wherein the contact sensor device (15, 16) is arranged separately from the spectrometer device (10).

13. A method (20) for operating a spectrometer device (10) according to any one of claims 1 to 12, the method comprising the following steps: placing (22) the spectrometer device (10) relative to the sample (18); checking (23) whether there is contact (19) between the spectrometer device (10) and the sample (18); If the contact (19) exists between the sample (18) and the spectrometer device (10), at least one operating parameter of the light source (11) and the detection device (12) is changed.

14. The method according to claim 13, wherein the detection of the spectrum is activated only when there is contact (19) between the spectrometer device (10) and the sample (18).

15. The method according to claim 13, wherein the detection of the spectrum is activated with a higher illumination intensity when there is contact (19) between the spectrometer device (10) and the sample (18) than when there is no contact.

16. The method according to any one of claims 13 to 15, wherein a prompt signal can be output to a user when there is no contact between the spectrometer device (10) and the sample (18).

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