초록 ▼

A device and a method for automatically inspecting objects traveling in an essentially monolayer flow. The device comprises a detection unit through which the object flow passes, consisting of the following: elements for applying electromagnetic radiation in the direction of the plane of conveyance

A device and a method for automatically inspecting objects traveling in an essentially monolayer flow. The device comprises a detection unit through which the object flow passes, consisting of the following: elements for applying electromagnetic radiation in the direction of the plane of conveyance of the objects and defining a lighting plane, the intersection of the lighting plane and plane of conveyance defining a detection line; a receiver device periodically scanning each point on the detection line and receiving radiation reflected by an elementary measuring zone, the plane defined by the detection line and the optical input center being known as the scanning plane; elements for transmitting the reflected radiation. The radiation emitted is concentrated in the region of the lighting plane and the lighting plane and the scanning plane merge, whereupon the joint plane is inclined in relation to the normal of the plane of conveyance.

대표청구항 ▼

The invention claimed is: 1. Machine for automatically inspecting objects travelling substantially in a single layer on or over a plane of conveyance of a conveyor, for discriminating between these objects by their chemical composition, said machine comprising at least one detection station through

The invention claimed is: 1. Machine for automatically inspecting objects travelling substantially in a single layer on or over a plane of conveyance of a conveyor, for discriminating between these objects by their chemical composition, said machine comprising at least one detection station through or beneath which the flow of objects passes, said detection station comprising: means for applying electromagnetic radiation in the direction of the plane of conveyance, emitting said radiation so as to define a lighting plane, the intersection of said lighting plane and said plane of conveyance defining a lighting line extending transversely to the direction of travel of the objects, a receiver device periodically scanning each point on said lighting line and receiving radiation reflected by an elementary measuring zone located in the region of the point scanned at this instant, the plane defined by said lighting line and the optical input centre of said device being known as the detection plane, means for transmitting to at least one analysis device said radiation reflected in the region of the scanning elementary measuring zone, wherein the emitted radiation is concentrated in the region of the lighting plane and wherein said lighting plane and the detection plane coincide as a common plane being inclined to the perpendicular to the plane of conveyance. 2. Machine according to claim 1, characterised in that the receiver device (8) comprises a moving reflective member (8 ') carrying the optical input centre (8"), directly receiving the radiation reflected in the region of the scanning elementary measuring zone (12) and having dimensions which are substantially equal to the dimensions of said elementary measuring zone (12) which it displaces, preferably substantially greater. 3. Machine according to claim 1, characterised in that the application means consist of broad spectrum lighting means, the applied radiation consisting of a mixture of electromagnetic radiation in the visible range and in the infrared range and in that said lighting means comprise members which concentrate the emitted radiation in the region of the plane of conveyance on a transverse detection strip (7') periodically scanned by the elementary measuring zone and of which the longitudinal median axis corresponds to the lighting line. 4. Machine according to claim 1, characterised in that the means (6) for application of radiation consist of two mutually spaced application units disposed in an alignment which is transverse to the direction of travel of the objects (2), each unit comprising an elongate emission member (6") combined with a member (6') in the form of a profiled reflector of elliptical section. 5. Machine according to claim 4, characterised in that each elongate emission member (6") is positioned substantially in the region of the near focus (F) of the reflector (6') associated therewith, the means for applying radiation (6) being positioned and the reflectors (6') being shaped and dimensioned in such a way that the second, remote focus (F') is located at a distance from the plane of conveyance (3) substantially corresponding to the mean height (H) of the objects (2) to be sorted, said focuses (F, F') being located in the lighting plane (Pe). 6. Machine according to claim 3, characterised in that walls (13, 13') reflecting the radiation emitted by the application means (6) are disposed along the lateral edges of the conveyor (3), in particular in the region of the ends of the detection strip (7'), and extend horizontally and vertically, substantially to the height of said application means (6). 7. Machine according to claim 3, characterised in that the receiver device (8) is in the form of a receiver head carrying, on the one hand, a moving reflective member (8') in the form of a plane mirror disposed substantially centrally relative to the plane of conveyance (Pc) of the conveyor (3) and oscillating by pivoting with a range which is sufficient for the moving elementary measuring zone (12) to explore the entire detection strip (7') during a half-oscillation and, on the other hand, a means (9) for focusing the fraction of radiation reflected by an elementary portion of the detection strip (7') and transmitted by the oscillating mirror ( 8') in the direction of said means (9), said head (8) also carrying the end which has the inlet orifice (10') of the means (10) for transmitting said fraction of radiation, after it has been focused by the means (9), toward at least one spectral analysis device (11, 11'). 8. Machine according to claim 7, characterised in that the focusing means (9) and the successive transmission means (10 ) are located outside the field of exploration (C) of the oscillating mirror (8') located in the scanning plane (Pb), the axis of alignment of the mirror (8')/focusing means (9)/inlet orifice (10') being located in said scanning plane (Pb). 9. Machine according to claim 7, characterised in that the oscillating plane mirror forming the moving reflective member (8') is located between the two units forming the means for applying radiation (6) and in a relative disposition which is such that said units do not interfere with the field of exploration (C) of said mirror (8') . 10. Machine according to claim 1, characterised in that the transmission means (10) consist of a bundle of optical fibres ( 10") all or the majority of which are connected to an analysis device (11) which breaks down the reflected radiation into its various spectral components and determines the intensities of some of said components having wavelengths which are characteristic of the substances of the objects to be sorted, said optical fibres (10") having a square or rectangular section arrangement in the region of the inlet orifice (10'). 11. Machine according to claim 10, characterised in that a minority of the optical fibres (10") of the beam (10) is connected to an analysis device (11') which detects the respective intensities of the three basic colours. 12. Machine according to claim 10, characterised in that the analysis device (11) consists, on the one hand, of a spectrometer (14) with a diffraction grating (14') which breaks down the multispectral light flux (14") received from the elementary measuring zone (12) into its various constituent spectral components, in particular into the infrared range, on the other hand, of means (15) for recovering and transmitting the elementary light fluxes (14'") corresponding to various unevenly spaced ranges of the spectrum, characterising the chemical substances and compounds of the objects (2) to be discriminated, for example in the form of separate bundles of optical fibres and, finally, of photoelectric conversion means (16) which deliver an analogue signal for each of said elementary light fluxes (14'"). 13. Machine according to claim 12, characterised in that the multispectral light flux (14") is introduced into the spectrometer (14) in the region of an inlet slot (17) and in that the elementary light fluxes (14'") are recovered in the region of outlet slots (17') having a shape and dimensions identical to those of the inlet slot and positioned as a function of the dispersion factor and of the ranges of the spectrum to be recovered, the end portions for the egress of the fibres (10") of the major component of the fibre bundle forming the transmission means (10) and the end portions for the ingress of the optical fibres (15') of the recovery and transmission means (15) having identical linear arrangements and being mounted in the inlet slot (17) and the outlet slots (17') respectively. 14. Machine according to claim 13, characterised in that the end portions for ingress of the optical fibres (15') of the bundles forming the recovery and transmission means (15) are mounted in thin plates (18) provided with appropriate receiving recesses (18') preferably combined with holding and locking back-plates (19) so as to form assembly and positioning supports ( 20) for said optical fibres (15') in the body of the spectrometer (14). 15. Machine according to claim 14, characterised in that the body of the spectrometer (14) comprises a rigid receiving and holding structure (21) with locking for said supports (20), which enables them to be positioned by sliding and to be installed by stacking, optionally with insertion of appropriate shims (22) so as to position said supports (20) in the locations corresponding to the impact zones of the elementary light fluxes (14'") to be recorded. 16. Machine according to claim 3, characterised in that it also comprises a unit (23) for processing and managing operation of the detection station (4) such as a computer controlling, in particular, the movement of the moving reflective member (8') and optionally of the conveyor (3), sequencing the acquisition of the radiation reflected in the region of the moving elementary measuring zone (12) and processing and evaluating the signals transmitted by the analysis devices (11, 11'), for example by comparison with programmed data, in order to determine the chemical composition of each of the inspected objects (2) or the presence of a chemical substance in said objects (2), by correlating the results of said determination with determination of the spatial location of said objects (2) as the case may be. 17. Machine according to claim 16, characterised in that the detection strip (7') has the form of an elongate rectangular surface of small width extending perpendicularly to the median axis and transversely over the entire width of the plane of conveyance (Pc) of the conveyor (3). 18. Machine for automatically sorting objects according to their chemical composition, these objects travelling substantially in a single layer on a conveyor, this sorting machine comprising an upstream detection station which is functionally coupled to a downstream station for active separation of said objects as a function of the results of the measurements and/or analyses effected by said detection station, characterised in that the detection station (4) is a detection station according to claim 1. 19. Sorting machine according to claim 18, characterised in that the detection station (4) or its unit (23) for processing and managing operation transmit actuating signals to a control module (24) for the ejection means (5') in transverse alignment of the active separation station (5) as a function of the results of said analyses, a salvo of actuating signals being emitted after each complete exploration of a transverse detection strip (7 ') by the moving elementary measuring zone (12). 20. Sorting machine according to claim 18, characterised in that the detection line (7) is located in the immediate vicinity of, for example at less than 30 cm from the ejection means (5'), for example by lifting, in the form of a row of nozzles which deliver jets of gas, preferably air. 21. Method for automatically inspecting objects travelling substantially in a single-layer on or over a plane of conveyance of a conveyor, said method allowing discrimination between said objects by their chemical composition and comprising: passing the flow of objects to be inspected through or beneath at least one detection station, emitting electromagnetic radiation toward the plane of conveyance via corresponding application means so as to define a lighting plane, the intersection of said lighting plane and said plane of conveyance defining a lighting line extending transversely to the direction of travel of the objects, periodically scanning any point on said lighting line via a receiver device which receives, at any instant, the radiation reflected by an elementary measuring zone located in the region of the point scanned at this instant, the plane defined by said lighting line and the optical input centre of said device being known as the detection plane, transmitting said radiation reflected in the region of the scanning elementary measuring zone to at least one analysis device via appropriate transmission means, wherein the radiation emitted is concentrated in the region of the lighting plane and wherein said lighting plane and the detection plane are combined as a common plane being inclined to the perpendicular to the plane of conveyance. 22. Method according to claim 21, characterised in that it involves concentrating the radiation, preferably in the visible and infrared range, in the region of the plane of conveyance on a transverse detection strip which is periodically scanned by the elementary measuring zone and of which the longitudinal median axis corresponds to the lighting line, so as to obtain high intensity of radiation which is substantially uniform over the entire surface of said detection strip. 23. Method according to claim 21, characterised in that it involves sequentially scanning the detection strip (7') with the moving elementary measuring zone (12) by pivoting oscillation of a plane mirror forming the reflective member (8'), focusing the light flux originating from the elementary measuring zone (12) on the inlet orifice (10') of the transmission means (10) in the form of a bundle of optical fibres (10"), bringing the majority of the captured multispectral light flux (14") toward the inlet slot (17) of a spectrometer (14) forming part of a first means of analysis (11), breaking down this light flux ( 14") into its various elementary spectral components (14'"), recovering the light fluxes of some of these components corresponding to specific narrow wavelength ranges in the region of outlet slots (17 ') and transmitting them via appropriate means (15) to photoelectric conversion means (16) in order to supply first measuring signals, simultaneously to bring, as the case may be, a small portion of the captured multispectral light flux (14") toward a second analysis means (11') determining the respective intensities of the three basic colours and supplying second measuring signals, processing said first and optionally second measuring signals in the region of a computerised processing and management unit (23) controlling, in particular, the movement of the moving reflective member (8'), sequencing the acquisition of the radiation reflected in the region of the moving elementary measuring zone (12) and processing and evaluating the signals transmitted by the analysis devices (11, 11') by comparison with programmed data in order to determine the chemical composition of each of the inspected objects (2) or the presence of a chemical substance in said objects (2). 24. Method according to claim 23, characterised in that it involves causing the unit (23) to transmit, as a function of the results of processing of the measuring signals, actuating signals to a module (24) for controlling ejection means (5') of a separation station (5') located downstream of the detection station (4) relative to the flow of objects (2) and, finally, ejecting or not ejecting each of the various objects (2) travelling on the supporting plane of conveyance (Pc) of the conveyor ( 3) as a function of the transmitted actuating signals. 25. Method according to claim 24, characterised in that a salvo of actuating signals is emitted on completion of each scanning of the detection strip (7') and processing of the corresponding measuring signals, taking into account the measuring signals of the previous scanning as the case may be.