WO2009146476A1

WO2009146476A1 - Method and measuring instrument for simultaneously determining elements of the mueller matrix of objects

Info

Publication number: WO2009146476A1
Application number: PCT/AT2009/000227
Authority: WO
Inventors: Abdulrasagh Aziz; Kirmanj Aziz
Original assignee: Abdulrasagh Aziz; Kirmanj Aziz
Priority date: 2008-06-05
Filing date: 2009-06-05
Publication date: 2009-12-10
Also published as: AT506599A4; EP2288901A1; AT506599B1

Abstract

The application relates to a method for determining all the desired elements of the Mueller matrix of an object by simultaneous measurements, wherein the beam bundles of an irradiation system (B), comprising two to four beam bundles (SP1 to SP4) from two to four radiation sources, which have various polarization states, interact with the object and the intensities of the two to four beam bundles are simultaneously measured, after interaction, in a sensor unit (SE) and the desired elements of the Mueller matrix are calculated on the basis of said measurements; and a measuring instrument for the simultaneous measurement for determining the desired elements of the Mueller matrix.

Description

METHOD AND MEASURING DEVICE FOR THE SIMULTANEOUS DETERMINATION OF ELEMENTS OF THE

MILLERMARKETRIX OF OBJECTS

The present invention relates to a method and a measuring device for the simultaneous determination of desired elements (or parameters), e.g. of up to 16 elements, such as all 16 elements of the millimeter matrix of objects to be identified using polarized light, which method and measuring device can be used for the automated detection of plastics.

Concepts for the use of polarized light for the automated detection of plastics are known. In this case, a polarization state (linearly polarized light or circularly polarized light) is used to illuminate the objects and the change in this state is detected. With such a method, it can be determined whether an object has an influence on polarized light, but does not cause which effect to change the polarization state. Such concepts are primarily used to distinguish crystalline and amorphous materials.

The interaction between quasi-monochromatic light and an object is mathematically determined by the matrix equation:

S ^' = MS

shown, where

S State of polarized light after interaction.

Initial Stock Vector (1X4 matrix) S state of polarized light before the interaction.

Input -Vector (1X4 matrix) M miller matrix (polarization properties of the object .A 4X4 matrix)

The miller matrix contains all the information about the polarization properties of an object. For the determination of the complete miller matrix, namely all elements of the Muller matrix, four different polarization states (eg: Linear Horizontal S _H , Linear Vertical S _v , Linear 45 ° S _p and Right Circular S _R ) for irradiating the object and four analyzer settings for measuring the polarization states modified by the interaction with the object ( eg S _H , S _v , S _p , S _R ). Altogether 16

Intensity measurements with different combinations of polarizer and analyzer setting (e.g., HH, HV, HP, HR, VH, VV, ...).

However, if non-depolarizing objects are examined, it can be shown that the miller matrix has only seven degrees of freedom. In this case, nine intensity measurements are sufficient to determine the complete miller matrix.

Assuming that the depolarization of linearly polarized light does not depend on its orientation, it is only possible to calculate nine elements of the miller matrix with linear polarizers (nine intensity measurements) and from these the independent parameters such as linear delay, circular deceleration, linear depolarization and linear Determine diattenuation. This assumption applies to cloudy objects.

Furthermore, one is often interested only in certain polarization properties of the objects to be examined. e.g .:

Diattenuation: To determine the diattenuation four measurements are necessary. It is a

Construction with four radiation sources to realize. Linear Diattenuation: To determine the linear diattenuation are only three

Measurements necessary. It is a construction with three radiation sources to realize. Circular Diattenuation: To determine the circular Diattenuation are only two

Measurements necessary. It is a construction with two radiation sources to realize.

Polarimeters and ellipsometers are laboratory instruments for the determination of miller matrices. In the laboratory these are used to measure layer thickness, refractive index, etc. There are various arrangements for the realization of polarimeters, or ellipsometers. However, these determine the elements of the miller matrix by sequential measurements. So far, no method for determining all desired, for example all 16 elements of the miller matrix, by simultaneous measurements, for automated object identification known. It has now surprisingly found a method for simultaneously determining all desired elements of the miller matrix, for example all 16 elements of the miller matrix, by simultaneous measurements of objects to be identified using polarized light.

In one aspect, the present invention provides a method for determining all desired elements of the miller matrix, for example all 16 elements (or parameters) of the miller matrix, of an object by simultaneous measurements, characterized in that the radiation beams of an irradiation system consisting of two to four beams, such as four beams, from two to four radiation sources, such as four radiation sources having different polarization states, interacting with the object and the intensities of the two to four beams, such as four beams, measured for interaction simultaneously and from these Measurements the desired elements, eg all 16 elements, the miller matrix will be calculated.

A method according to the present invention involves determining a part and not just all elements of the miller matrix by simultaneous measurements by combining two to four beams having different states of polarization.

The invention will now be described by way of embodiments with reference to FIGS

Drawings explained in more detail. In the drawings show schematically:

Fig. 1 is an irradiation system with four radiation sources with different

Spectral regions for irradiating an object;

FIG. 2 shows a sensor unit with four sensors for evaluating four radiation beams with which an object was irradiated; FIG.

3 shows a transmission method for determining the complete miller matrix of a

object;

FIG. 4 shows a reflection method for determining the complete miller matrix of an object; FIG.

5 shows a further sensor unit with four sensors for the evaluation of four beams with which an object was irradiated;

Fig. 6 in turn another sensor unit with four sensors for the evaluation of four

Beams with which an object was irradiated; and

7 shows a sensor unit with an area sensor with combination pixels. Description of the pictures

Fig. 1 shows an irradiation system consisting of 4 radiation sources, each with different spectral ranges (radiation sources Sl to S4), in which the 4 beams polarized by means of polarizers Pl to P4 respectively and then with the aid of beam combiners BCl, BC2 and BC3 are combined into a beam STR consisting of four differently polarized beams.

Fig. 2 shows a sensor unit which consists of four sensors SEN1 to SEN4. The beam bundle STR 'entering the sensor unit is divided into four beam bundles by means of beam splitters STT1 to STT3. These fall apart on the sensors. In front of each sensor is an optical system consisting of an analyzer A1 to A4 with a specific polarization setting and spectral splitting optics sOPl to sOP4, using a transmission or reflection grating. With the help of the optics, the beams are split in their spectra and projected on the sensors SEN1 to SEN4.

3 shows a transmission method for determining the complete miller matrix of an object from simultaneous measurements in which an irradiation unit "B" according to FIG. 1 is used (SP1 to SP4 in each case denote beams with polarization states 1 to 4) four differently polarized radiation beams, it is passed through the sample to be examined ("object"), whereupon in a sensor unit "SE" shown in FIG. 2, the change in the polarization of the four beams is measured.

4 shows a reflection method for the determination of the complete miller matrix of an object, from simultaneous measurements, in which a radiation unit "B" according to Figure 1 is used (SP1 to SP4 respectively denote ray bundles with polarization states 1 to 4) consists of four differently polarized radiation beams, it is then directed to the sample to be examined ("object"), whereupon in a sensor unit "SE" of FIG. 2, the change in the polarization of the four beams is measured. Fig. 5 shows a sensor unit consisting of four sensors SEN1 to SEN4. The radiation beam STR 'entering the sensor unit is divided into four beams by beam splitters STT1 to STT3. These fall apart on the sensors. In front of each sensor is an optic consisting of an analyzer Al to A4 with a specific polarization setting. Each sensor consists of composite pixels consisting of four smaller pixels. In this case, each composite pixel consists of 4 smaller pixels coated with four different color filters. The color filters can be arranged differently. One of the possible arrangements is shown in FIG.

Fig. 6 shows a sensor unit consisting of four sensors SEN1 to SEN4. The beam bundle STR 'entering the sensor unit is divided into four beam bundles by means of beam splitters STT1 to STT3. These fall apart on the sensors. Before each sensor is a color filter (FFl to FF4). Each sensor consists of combi-pixels consisting of four smaller pixels coated with polarizing filters. The polarizing filters can be arranged differently. One of the possible arrangements is shown in FIG.

7 shows a sensor unit in which the four bundles of rays coming from the object are split into their spectra by means of spectral splitting optics and projected onto a surface sensor with combi-pixel, which is coated with polarization filters.

An irradiation system which can be used, for example, according to the present invention consists of two to four radiation sources. From the radiation sources, two to four beams, for example STR1, STR2, STR3 and STR4, emit arbitrary, but different spectral ranges. The beams are polarized differently, for example with the aid of polarizers, and reunited, for example using the Beam Combiner (BC) method, ie with the aid of several BCs. For example, with the aid of a BC (BCl), the polarized radiation beams STR1 and STR2 are combined from two radiation sources 1 and 2; and with the aid of another BC (BC2), the already combined radiation beams STR1 and STR2 are combined with a polarized radiation beam STR3 from the radiation source 3. With the help of a third BC (BC3) four beams are then combined in a beam and it creates a beam STR, which consists of two to four differently polarized radiation beams. With this combined beam, the object to be examined is irradiated. A possible arrangement with four beams STR1 to STR4 is shown for example in FIG. In another aspect, the present invention provides a method of the present invention in which two to four beams, for example four beams, are differently polarized prior to interaction with the object and combined into a beam, optionally with the aid of beam combiners , with which the object to be examined is irradiated, z. As shown in FIG. 1, wherein an arrangement is shown in which four beams are used.

The changes in polarization states are then measured with a sensor unit. Such sensor units and corresponding measuring methods include sensor units and corresponding measuring methods, such as e.g. herein in variant 1, variant 2 and variant 3, with a. As can be seen from the following description, the sensor units simplify in the determination of only a part of the elements of the miller matrix compared to the determination of all elements of the miller matrix, so the complete miller matrix. For example, in a setup according to variant 1, one only needs a single sensor in order to determine the diatuation.

version 1

The changes in polarization states are measured with a sensor unit consisting of one to four sensors. For the determination of only a desired part, that is to say not all 16 elements of the miller matrix, the number of sensors can be correspondingly reduced, for example only one single sensor is needed to determine the diurnal rate.

The beam entering the sensor unit is split into two to four beams with beam splitters. These fall apart on the sensors. In front of each sensor is an optic which consists of an analyzer with a specific polarization setting and spectral splitting optics, for example using a transmission or reflection grating. With the help of the optics, the beams are split in their spectra and projected on area sensors; for example, according to or analogously to FIG. 2. In this way, the intensities of the two to four beam bundles are measured with the sensor unit, thereby determining the desired, for example all 16, elements of the miller matrix. In another aspect, the present invention provides a method according to the invention wherein the intensities of the two to four beams, for example the four beams, are measured by means of a sensor unit consisting of one to four sensors, for example four sensors. wherein there is an optical system in front of each sensor, which consists of an analyzer with a specific polarization setting and a spectral splitting optics, for example using a transmission or reflection grating; for example, according to or analogous to FIG. 2, in which four beams are used.

Variant 2

The intensities of the beam can also without grating for spectral cleavage means

Sensors with combi pixels are measured.

In one case, each combi-pixel of the sensors consists of two to four smaller pixels coated with two to four different color filters, which color filters may be arranged differently, e.g. if only a desired part of the miller matrix is to be determined ..

In another case, each combi-pixel of the sensors consists of one to four smaller pixels coated with different polarizing filters, each of the two to four sensors being irradiated with an associated spectrum, e.g. in the case of four sensors for determining all elements of the miller matrix.

In another case, each combi-pixel of the sensors consists of four smaller pixels coated with four different color filters, the color filters being arranged differently. A corresponding, possible arrangement is shown in Fig. 5.

In another case, each combi pixel of the sensors consists of four smaller pixels coated with different polarizing filters, each of the four sensors being irradiated with an associated spectrum. A corresponding, possible arrangement is shown in Fig. 6. In another aspect, the present invention provides a method according to the invention wherein the intensities of the two to four beams are measured by means of a combined pixel sensor unit,

each combi-pixel of the sensors consists of two to four smaller pixels coated with different color filters; e.g. analogous to FIG. 5; for example, the intensities of the four beams are measured by means of a combi pixel sensor unit, each combi pixel of the sensors consisting of four smaller pixels coated with four different color filters; e.g. as shown in Figure 5, or

each combi-pixel of the sensors consists of one to four smaller pixels coated with different polarizing filters and wherein each of the two to four sensors is irradiated with an associated spectrum; e.g. analogous to FIG. 6; for example, each combi pixel of the sensors consists of four smaller pixels coated with different polarizing filters, each of the four sensors being irradiated with an associated spectrum; e.g. according to FIG. 6.

Variant 3

With a spectral splitting optics, the beam entering the object from the object is split into its spectra and projected onto a surface sensor with combi pixels coated with polarization filters (Al to A4). A corresponding, possible arrangement is shown for example in Fig. 7.

In general, with spectral splitting optics, the beam entering the object from the object is split into its spectra and projected onto a surface sensor with combi-pixels which are coated with 1 to 4 polarization filters.

In a further aspect, the present invention provides a method according to the present invention, wherein the two to four, in particular four, of the object coming bundle of rays by means of a spectral splitting optics in their spectra split and on a surface sensor with combi-pixel, which is coated with polarizing filters , in particular one to four, in particular four, polarizing filters are projected; for example, analogously or as shown in Fig. 7. A method according to the invention may consist in a transmission arrangement, that is, the beam consisting of the two to four beams is passed through the object, whereupon the changes in the polarization of the two to four beams are measured; or in a reflection arrangement, that is, the beam consisting of the two to four beams is directed to the object and reflected by the object, whereupon the changes in the polarization of the two to four beams are measured.

The measurement of the change in the polarization of the two to four beams can be made in all possible embodiments, e.g. analogously or according to variants 1 to 3, as described herein.

FIG. 3 schematically shows a method according to the present invention in a transmission arrangement and with a sensor unit according to variant 1.

FIG. 4 schematically shows a method according to the present invention in reflection arrangement and with a sensor unit according to variant 1.

In another aspect, the present invention provides a method of the present invention wherein the radiation beams of the irradiation system interact with the object in transmission arrangement; e.g. analogously or according to FIG. 3.

In a further aspect, the present invention provides a method according to the present invention, wherein the radiation beams of the irradiation system interact with the object in reflection arrangement; e.g. analogously or according to FIG. 4.

From the particular elements, e.g. all 16 elements of the miller matrix of the objects to be identified and, e.g. By comparison with values obtained from known objects, the nature of the object, e.g. based on its physical properties, e.g. Polarization properties are determined.

A method according to the present invention can therefore be used for object identification, eg for the recognition of the condition of an object, eg on the basis of its physical properties, eg on the basis of its polarization properties. A method according to the present invention can be used for

- distinction of objects,

Recognition of the nature of an object for distinguishing objects,

- automated differentiation of objects,

- Identification of several different, next to each other and / or successively moving objects used; e.g. based on the different physical properties of objects, e.g. on

Based on their different polarization properties.

The size, speed and number of objects, as well as the width of the field of view are arbitrary and determined only by the resolution of the measuring sensors.

In a particular embodiment, the use of a method according to the invention involves the sorting of different plastics, e.g. the sorting of PET, PVC.

The use of a method of the present invention includes a method for, preferably automated, sorting objects from a waste composition.

In another aspect, the present invention provides a simultaneous measurement meter for determining the desired elements of the miller matrix of objects, characterized in that it comprises: a) an irradiation system having two to four, preferably four, radiation sources (S 1 to S4), which are designed to emit two to four, preferably four beams, with which an object can be irradiated, the beams are each polarizable and have different polarization states, b) sensors (SENl to SEN 4), with which the intensities of the two to four, preferably four, radiation beam after irradiation and resulting interaction with an object are simultaneously measurable-are, and c) a computer that calculates the desired, in particular all 16, elements of the miller matrix from these measurements and available; wherein the measuring device is optionally coupled with a, preferably automated, system with which the distinction and sorting of various objects on the basis of their miller matrices from several different, side by side and / or successively moving objects, vornehmbar to a predetermined location.

A calculator that simultaneously obtains from these measurements elements e.g. For example, all 16 that calculates and makes available miller matrix is a computer.

An irradiation system and sensors include an irradiation system and sensors as described above, for example an irradiation system according to FIG. 1 and sensors according to variants 1 to 3, for example as shown in FIGS. 2 and 5 to 7.

The meter may e.g. be equipped with a transmission arrangement or with a reflection arrangement, such. described above, e.g. according to one of the Fig. 3 or 4, wherein the sensor part may correspond to one of the embodiments according to one of the Fig. 2, or 5 to 7.

A measuring device according to the present invention may be adapted for use according to the use of a method according to the invention, e.g. as described above.

Claims

claims

1. A method for determining all desired elements of the miller matrix, in particular all 16 elements of the miller matrix, of an object by simultaneous measurements, characterized in that the radiation beams of an irradiation system consisting of two to four beams, in particular four beams, from two to four radiation sources, in particular four radiation sources, which have different polarization states, interact with the object and the intensities of the two to four beams, in particular four beams, measured by interaction simultaneously and calculated from these measurements, the desired elements, in particular all 16 elements of the miller matrix.

2. The method of claim 1 for determining all 16 elements of the miller matrix, characterized in that the radiation beams of an irradiation system, consisting of four beams of four radiation sources having different polarization states, interact with the object and the intensities of the four beams after interaction measured simultaneously and from these measurements all 16 elements of the miller matrix are calculated.

3. The method according to any one of claims 1 or 2, characterized in that the beams are differently polarized before the interaction with the object and combined into a beam, whereby the object to be examined is irradiated.

4. The method according to any one of claims 1 to 3, characterized in that the intensities of the two to four, beam are measured by means of a sensor unit consisting of one to four sensors, wherein in front of each sensor is an optic consisting of a Analyzer with a specific polarization setting and a spectral splitting optics is, in particular using a transmission or reflection grating.

5. The method according to any one of claims 1 to 3, characterized in that the intensities of the two to four beams are measured by means of a sensor unit with Kombipixel, each combi-pixel of the sensors consists of two to four smaller pixels coated with different color filters; in particular, the intensities of the four beams are measured by means of a sensor unit with combi-pixels, each combi-pixel of the sensors consisting of four smaller pixels coated with four different color filters; or

each combi-pixel of the sensors consists of one to four smaller pixels coated with different polarizing filters and wherein each of the two to four sensors is irradiated with an associated spectrum; wherein in particular each combination pixel of the sensors, in particular four sensors, consists of four smaller pixels which are coated with different polarization filters, and wherein each sensor, in particular each of the four sensors, is irradiated with an associated spectrum.

6. The method according to any one of claims 1 to 3, wherein the two to four, in particular four, coming from the object beam with the aid of a spectral splitting optics split in their spectra and on a surface sensor with combi-pixel, which is coated with polarizing filters, in particular one to four , in particular four polarizing filters, are projected.

A method according to any one of claims 1 to 6, wherein the radiation beams of the irradiation system interact with the object in transmission arrangement.

8. The method according to any one of claims 1 to 6, wherein the radiation beams of the irradiation system interact with the object in reflection arrangement.

9. A simultaneous measurement device for determining the desired elements of the miller matrix of objects, characterized in that it comprises a) an irradiation system with two to four, preferably four radiation sources (S 1 to S 4), which are formed two to four, preferably four beams to emit, with which an object can be irradiated, wherein the beams are each polarizable and have different polarization states, b) sensors (SEN1 to SEN 4), with which the intensities of the two to four, preferably four, beams, after irradiation and the resulting interaction with an object are simultaneously measurable, and c) a computer, from these measurements the desired, especially all 16, computes and makes available elements of the miller matrix.

10. Measuring device according to claim 9, characterized in that it is coupled to a, preferably automated, system with which the distinction and sorting of different objects based on their miller matrices from several different, side by side and / or successively moving objects to a predetermined Place is vornehmbar.