WO2008041124A1

WO2008041124A1 - A method and device for quality inspection of vegetable produce

Info

Publication number: WO2008041124A1
Application number: PCT/IB2007/003025
Authority: WO
Inventors: Dario Beltrandi; Massimo Balducci
Original assignee: Sacmi Cooperativa Meccanici Imola Societa' Cooperativa
Priority date: 2006-10-06
Filing date: 2007-10-02
Publication date: 2008-04-10

Abstract

A device for quality inspection of items (100) of fruit and vegetable produce, comprises means for sequentially locating the items (100) to be inspected in a predetermined inspection position along a predetermined path comprising the predetermined inspection position, means for illuminating (3) for projecting light rays on an item (100) in the inspection position, and a sensor organ (40) which captures at least a portion of light refracted from the item (100) following exposition thereof to the light rays, and which transmits the portion of refracted light to a spectroscope, the sensor organ (40) being located vertically below the item (100) in the inspection position. The device also comprises at least partly-independent means for guiding at least a part of the light refracted to the sensor organ.

Description

A METHOD AND DEVICE FOR QUALITY INSPECTION OF VEGETABLE PRODUCE

Technical Field

The invention relates to a method and a device for inspecting the quality of vegetable produce, typically fruit, by projecting rays of light onto each item to be inspected and spectographically analysing the fraction of light which is refracted from the produce. Background Art

Spectrographic analysis of refracted light enables measurement of some important characteristics of fruit and vegetable produce, such as sugar or acidity levels, from which qualitative information can be derived, such as for example the degree of ripeness. Device which are at present used for performing this type of inspection generally comprise a conveyor which advances the vegetable produce in a predetermined course, along which they pass one at a time through an inspection position. Means for illuminating are present at the inspection position, which project very intense rays of light from different angles onto the transiting item of produce, and means for receiving, which capture at least a portion of the refracted light from the item and transmit it to a spectroscope. The means for illuminating typically comprise a plurality of high-potential halogen lamps, which are positioned along the flanks of the transporter and are arranged such as substantially to surround the item of produce which is in the inspection position.

The prior art teaches that in order to obtain reliable information on the internal quality of the food, it was necessary to illuminate a large surface of the vegetable and preferably from various directions; this was because vegetable produce often exhibits internal zones having non-uniform characteristics, which must all be passed-through by the light in order to provide information on the general quality of the item of produce. The means for receiving comprise an optical sensor group, usually known as a collimator, which is located below the conveyor at the inspection position.

The collimator generally comprises a vertical-axis cylindrical tubular body which aligns with the vegetable produce in the inspection position. The portion of refracted light that enters the tubular body is conveyed towards the end of an optic fibre which is connected to a spectroscope located at distance.

A need of these inspection devices is that no light which is not the light refracted from the produce can penetrate internally of the collimator, so that no intolerable disturbance is created to disrupt the spectrographic analysis.

In particular, the collimator must not gather dispersed light, i.e. light coming directly from the means for illuminating or reflected from the item of produce being inspected, as the intensity of this light would render the measurements performed totally unreliable. To serve that need the conveyor usually comprises a sliding chain which at each step bears a cup-shaped seating on the edge of which the item of produce to be inspected is laid.

The seating constitutes a means for guiding the refracted light, preventing it from being polluted. The cup is provided with a vertical-axis central through-hole which is exactly aligned with the collimator when the cup is at the inspection position.

The central hole enables a portion of the light refracted from the vegetable to filter downwards, such that it can be gathered and concentrated by the underlying collimator. The distance between the collimator and the cup in the inspection position is generally very small, such that the cup functions as a barrier for preventing the dispersed light from reaching the collimator.

The known-type inspection devices exhibit a series of drawbacks which prevent their widespread use. A first considerable drawback is that the conveyor predisposed to prevent the dispersed light from reaching the collimator is very complicated and expensive. As previously mentioned, the chain of the conveyor must in fact comprise, for each step of the chain, a cup having a concavity facing upwards and holed at the centre.

The cup must also be shaped so that the product to be inspected sits perfectly on the edge of the mouth, without resting internally thereof, and at the same time guarantees stability of transport. This implies that the edge must exhibit a design and size which are suitable to receive only fruit and vegetable products having similar shapes and overall sizes comprised within a quite narrow range, which in turn implies that a same conveyor has to be equipped with cups of various shapes and measurements, suitable for example for pears, melons or apricots, simply to mention some fruits having considerably different sizes and shapes.

Since each conveyor comprises from 200 to 250 cups, it is easy to imagine the cost of the various series of cups that must be made available for a same conveyor.

A second drawback consists in the fact that the finite number of cups which can be installed on the conveyor places a structural limit on the load capacity of the conveyor, and thus on the productivity of the inspection device. A third drawback is that the special conformation of the conveyor creates large technical difficulties relating to integration of the known inspection devices in normal vegetable produce selection lines, which generally use simple sliding conveyor belts.

To obtain the integration special loading devices are required, which perform the operations of collecting the vegetable produce from the selection lines, positioning them and finally releasing them, each in a respective cup of the inspection device, respecting the step that separates each cup on the slidable chain.

The loading devices are constructionally complicated and expensive, and slow down the whole system of treatment of the vegetable produce, limiting its productivity. The aim of the present invention is to make available a method for inspecting the quality of the vegetable produce which obviates the above-mentioned drawbacks in the ambit of a simple, rational and inexpensive solution. A further aim of the invention is to make available a method for inspecting the quality of the vegetable produce which can use any type of known conveyor and therefore can be used with selection lines already in existence. Disclosure of Invention

The above-described aims are attained by the invention, as it is characterised in the appended claims. In particular, the invention provides a method for inspecting the quality of vegetable produce which comprises the operating stages of: supplying the items of vegetable produce in succession to a conveyor provided over a whole length thereof with a central opening; projecting at least a concentrated light beam on at least a portion of the external surface of each vegetable; using a sensor organ to capture at least a part of the light of the concentrated light beam which is refracted internally of each vegetable; guiding the refracted part of light to an instrument for spectrographic analysis, preventing pollution of the part of light by dispersed light, using means which are at least partly independent of the conveyor. With the method of the invention it is not necessary to adopt special constructional details to protect the light-receiving means from the dispersed light, making it possible to use any type of known conveyor, comprising a simple sliding conveyor belt. The means which guide the portion of refracted light to the analysis instrument are constituted, in the simplest embodiment, by an assembly of elastic walls which surround the sensor organ and which define a vertical corridor, which guides at least a portion of the refracted light from the vegetable in the inspection position towards the sensor device. In a further preferred embodiment, the means for guiding the refracted light to the means for receiving the refracted light are constituted by the following combination. The means for projecting the concentrated beam are arranged on opposite sides of the vegetable produce to be inspected, such that the light of the light beam is prevented from directly reaching the means for receiving. The light beam is preferably concentrated on a restricted surface of the vegetable item.

It has been observed that by illuminating only a small portion of the vegetable item, the refraction phenomena internally of the vegetable, known as scattering, enable the light to diffuse substantially in all directions and, thus to supply sufficiently reliable information relating to the internal quality. In a preferred characteristic of this embodiment, only a restricted portion of the vegetable is illuminated.

The decision to keep the illuminated part of the vegetable item small means drastically reducing the dispersed light which is produced during the inspection and therefore also reducing the danger of the dispersed light being captured by the means for receiving and compromising the spectroscopic analysis.

In a further preferred embodiment of the invention, the concentrated beam is obtained by means of a concentrating device which concentrates the light rays coming from at least a light source, such as to obtain a concentrated beam of light of predetermined dimensions.

The concentrating device is preferably of an optical type, typically a condenser lens which concentrates the rays originating from a plurality of distinct light sources, for example a plurality of halogen lamps. In a further preferred aspect of the further preferred embodiment of the invention, the means for receiving also comprise concentrator device, typically a condenser lens, which concentrates a portion of the refracted light exiting the vegetable produce, such as to obtain a high-energy beam which can easily be transmitted to the spectroscope, making the analysis more precise. The stages of concentrated beam projection and capturing of the refracted light are done internally of a light chamber which is isolated from the outside. The isolated chamber is delimited by a closed casing which effectively prevents inlet of environmental light, such that the light cannot be captured by the means for receiving and therefore alter the results of the spectroscopic analysis. The invention also makes available a device for actuating the method.

The device comprises a conveyor which advances a sequence of vegetable produce to be inspected along a predetermined path which comprises a predetermined inspection position; means for illuminating for projecting light rays onto the item of vegetable produce which is in the inspection position; a capturing organ which captures at least a portion of the refracted light from the item of vegetable produce, following exposure thereof to the light rays, as well as means which are at least partially independent of the conveyor for guiding the at least a part of the refracted light to the capturing organ. In the simplest embodiment of the device, the guide means comprise an assembly of elastic walls which surround the capturing organ and which define a vertical corridor, crossed by the vegetable item, which guides at least a portion of the refracted light from the vegetable in the inspection position towards the capturing device. In particular, the elastic walls project above the advancement plane defined by the conveyor and adhere to the surface of the vegetable in the inspection position, such that the vegetable superiorly closes the vertical corridor. In this way, when each single vegetable is in the inspection position, the vertical corridor defined by the elastic walls is perfectly closed, effectively preventing the disturbing light from penetrating internally and therefore reaching the capturing organ.

When the vegetable displaces from the inspection position, the walls delimiting the vertical corridor then re-acquire their original shape thanks to the elasticity thereof, such that they are ready to receive the following item. Thanks to this solution, as the elastic walls automatically adapt to the shape and size of the vegetable produce to be inspected, the device of the invention is able to operate with any type of produce without requiring any structural modification. In a further preferred embodiment, the guide means comprise a concentrator device which concentrates the light rays coming from at least a light source such as to obtain a concentrated beam of predetermined dimensions, which strikes the item of fruit. The concentrator device is preferably of optical type, typically a condenser lens which concentrates the rays coming from a plurality of distinct light sources, for example from a plurality of halogen lamps. In a further preferred aspect of the further preferred embodiment of the invention, the means for guiding typically comprise a condenser lens, which concentrates a portion of the refracted light exiting the item of vegetable produce, such as to obtain a high-energy beam which can easily be transmitted to the spectroscope, making the analysis more precise.

In this case too the device of the invention is able to operate with any type of produce, without any need for structural modifications to the transporter, and can use a normal conveyor. It is no longer necessary for the conveyor to be provided with a succession of cups, each supporting a respective item of produce to inspect, and can therefore be realised more simply, economically and functionally. In particular, in the invention the conveyor is of a continuous type and, preferably, simply comprises two slidable belts, parallel and reciprocally distanced, which contemporaneously support produce to be inspected.

Thanks to the simplicity of the continuously conveyor, the device of the invention provides the further advantage of inspecting imperfectly- equidistanced produce along the advancement path, making the stage of loading the vegetables onto the conveyor simpler and faster and increasing the overall load capacity of the conveyor. Brief description of the Drawings

Further characteristics and advantages of the invention will emerge from the following description, provided by way of non-limiting example with the aid of the figures of the accompanying drawings, in which: - figure 1 is a perspective view of an inspection device of at least a first embodiment of the invention, shown at the inspection position; - figure 2 is section IMI of figure 1 ; - figure 3 is section Ill-Ill of figure 2;

- figure 4 is a detail of the device of figure 1 ;

- figure 5 is the detail of figure 4 in a variant of the first embodiment of the invention; - figure 6 is section H-Il of figure 1 relating to the variant of the first embodiment of the invention;

- figure 7 is a variant of the detail of figure 4;

- figure 8 is figure 6 including the variant illustrated in figure 5;

- figure 9 is a perspective view of an inspection device in a further variant of the first embodiment of the invention, shown in the inspection position;

- figure 10 is section X-X of figure 9;

- figure 11 is section Xl-Xl of figure 10;

- figure 12 is a perspective view of a device according to a second embodiment of the invention; - figure 13 is the view denoted by XIII in figure 12;

- figure 14 is a perspective view of a first variant of the device of figure 12;

- figure 15 is the view denoted by XV in figure 14;

- figure 16 is a perspective view of a second variant of the device of figure 12;

- figure 17 is figure 16, showing in transparency the contents of the closed casing 106.

Best Mode for Carrying Out the Invention

Figures from 1 to 4 illustrate an inspection device 1 for items of fruit and vegetable produce 100 in a first embodiment of the invention. The device 1 comprises a continuous conveyor 2 for uninterruptedly advancing a sequence of items of produce 100 along a predetermined path, passing the items of produce one at a time into an inspection position. Illuminating means 3 are installed at the inspection position, for projecting high-intensity light rays on each item of produce 100 in transit. In particular, the illuminating means 3 operate continuously and constantly project the light rays only towards the inspection position, such as to illuminate each item 100 transiting through the inspection position for a brief time. Also installed at the inspection position are means for receiving 4 for receiving and concentrating at least a portion of the refracted light from each item of produce following exposition thereof to the light rays, then to send the refracted light on to a spectroscope (not illustrated) located at a distance, which spectroscope performs a spectrographic analysis of the light in order to detect internal qualitative characteristics of the item of produce 100. As illustrated in figure 1 , the continuous conveyor 2 comprises two parallel sliding belts 20, which contemporaneously support each item 100 to be inspected, and slide constantly at the same speed.

The sliding belts 20 are coupled to a respective guide and support rail 21 and are activated by a same motor group, which is not illustrated as it is of known type.

The sliding belts 20 are reciprocally distanced by a quantity sufficiently small to enable the items 100 to be rested thereon, and at the same time sufficiently big to guarantee the stability of the items during transport. The sliding belts 20 and the relative guides 21 are preferably associated to means for regulating (not shown) which vary the reciprocal distance according to the size and/or the shape of the items 100 of produce to be inspected. The illuminating means 3 comprise a large number of halogen lamps 30 located at a height which is not lower than the height of the advancement plane of the items 100 defined in the sliding belts 20. The halogen lamps 30 are sub-divided into two distinct groups arranged respectively on opposite sides with respect to the sliding belts 20.

Each group of lamps 30 is singly mounted on a respective box-shaped support 31 , which is in turn associated to a relative fixed support structure 32. The halogen lamps 31 are distributed on each box-shaped support 31 in the direction of the longitudinal direction of the sliding belts 20 and are distributed such as to project the light rays concentrically on the item 100 of produce which is in the inspection position from various positions and at different angles.

In particular, each group of halogen lamps 30 is arranged and orientated such that the light rays generated converge at a same focal point internally of the item 100 of vegetable produce in the inspection position.

Generally the focal points at which the light rays emitted by the two halogen light groups 30 converge are different from one another. As during functioning the halogen lamps 30 heat up considerably, a cooling system (not illustrated as of known type) is associated to each lamp group 30, which generates a jet of refrigerating fluid, typically air, which strikes the halogen lamps 30.

In this way, the refrigerating fluid dissipates the heat and prevents overheating of the lamps 30, improving the lamps' 30 performance and increasing their working life. Each box-shaped support 31 is coupled to the relative support structure 32 such as to be able to rotate with respect thereto about a rotation axis R which is parallel to the advancement path of the sliding belts 20, activated by a relative motor (not illustrated). Thanks to this solution, each halogen lamp group 30 can be selectively orientated such as to place the area surrounding the inspection position in shadow, for example by pointing the light rays upwards. This is done when there is a long shutdown of the sliding belts 20, for example for checking or maintenance, such as to prevent them from being damaged by the heat emitted from the halogen lamps 30. During functioning, the halogen lamps 30 cause great heating of the sliding belts 20, which can reach temperatures of up to 300⁰C.

As long as the belts 20 run, the heat to which they are subjected in the inspection position is dissipated in the remaining part of their path; when they are stopped, the heat is no longer dissipated and the risk of damage is extremely probable. In this case, the box-shaped supports 31 are rotated with respect to the relative support structures 32 in order to prevent the light rays emitted by the halogen lamps 30 from being directed towards the sliding belts 20. A situation in which the halogen lamps are switched off for a long period is, however, not advisable. The characteristics of the light rays emitted by the halogen lamps 30 strongly depend on the working temperature reached by the lamps 30. Therefore measurements done after a long switched-off period, with the halogen lamps 30 having cooled down, would inevitably be affected by a considerable and significant error factor. The means for receiving 4 comprise an optical sensor group 40, usually known as a collimator, which captures and concentrates at least a portion of the light refracted from the vegetable item 100 in the inspection position, such as to make the portion of light available to a spectroscope located at a distance (not illustrated). The collimator 40 is a known device in the sector of inspection devices in object and can be realised in different construction forms according to requirements.

In the illustrated example, it simply comprises a cylindrical tubular body orientated such that the central axis thereof 0 is vertically aligned with the item 100 which is in the inspection position. An optic fibre 38 is inserted in the cylindrical tubular body and exits from the lower end of the collimator 40, and is connected to the distance-located spectroscope. The upper end 39 of the cylindrical tubular body faces towards the vegetable item 100 located in the inspection position, and is closed by a transparent slide which protects the end of the optic fibre 38 located internally of the collimator 40 by extraneous bodies which might obstruct it. In this way, the portion of refracted light which enters the collimator 40 through the upper end 39 of the tubular body is conveyed to the internal end of the optic fibre 38, which guides the light towards the spectroscope. Alternatively, a lens system housed internally of the tubular body of the collimator 40 can be interposed between the protection slide and the internal end of the optic fibre 38.

The lens system has the function of collecting the light entering from the upper end 39 of the tubular body, such as to concentrate the light in a focal point which falls exactly at the internal end of the optic fibre 38. Obviously, should the size of the device permit it, the spectroscope could be directly connected to the collimator 40 without interposing any optic fibre. The collimator 40 is positioned in plan view in the space comprised between the sliding belts 20, at a lower level than them.

Further, the collimator 40 is oriented in a vertical direction such that the optical axis O thereof intercepts the item 100 passing through the inspection position.

A flat horizontal screen 41 is interposed between the collimator 40 and the sliding belts 20, which screens the collimator 40 from the light coming directly from the halogen lamps 30. The screen 41 exhibits a central opening 42 towards which the end of the inlet end 39 of the collimator 40 faces, such as to receive the refracted light from the item 100 of vegetable produce in the inspection position. Two first linear-developing brushes 43 are located on the flat screen 41 , which brushes 43 are parallel to the advancement path defined by the sliding belts 20 and are arranged on opposite sides of the inlet 39 of the collimator 40, and two second linear-developing brushes 44, which are transversal to the advancement path and are arranged respectively upstream and downstream of the inlet 39 of the collimator 40. In this way, the linear brushes 43, 44 define further elastic walls which overall form a salient rectangular frame which surrounds and surmounts the inlet 39 of the collimator 40.

In the illustrated embodiment, the frame of linear brushes 43, 44 is completely contained in the empty space between the sliding belts 20.

The function of the frame of linear brushes 43, 44 is to delimit a dark vertical corridor 45 which guides the refracted light from the item 100 in the inspection position towards the inlet 39 of the collimator 40, while contemporaneously creating a barrier which prevents disturbing light from entering the corridor 45 and thus from reaching the collimator 40.

In particular, the frame of linear brushes 43, and 44 has the function of preventing the collimator 40 from gathering the light reflected from the unit 100 following the exposition thereof to the light rays, or the light directly emitted by the lamps 30. As illustrated in the figures of the drawings, the linear brushes 43, 44 are structurally identical to one another, being different only in terms of the length thereof.

In particular, each linear brush 43, 44 comprises a longitudinally-developing support block 46 on which two distinct lines 47 of vertical bristles are fixed, vertically reciprocally separated by a space.

Each line 47 is formed by a plurality of flexible and elastic bristles arranged adjacent to one another and orderedly distributed to form a continuous wall along the longitudinal development of the support block 46. Obviously the flexible bristles of each line 47 must be sufficiently densely arranged in order to prevent disturbing light from filtering laterally into the inside of the corridor 45.

In this way, each brush 43, 44 comprises two distinct walls, opposite and parallel, of flexible bristles which, separated by the space, substantially provide a double barrier against the passage of the disturbing light. The flexible bristles belonging to the linear brushes 43, 44 project above the advancement plane of the items 100 defined by the sliding belts 20, such as to come into contact with and strike each item 100 transiting from the inspection position.

In this way, the bristles can flex, pushed by the item 100 in transit, and adapt to the particular shape of the item 100; this ensures that the upper end of the corridor 45 is always perfectly closed when the item 100 is in the inspection position, such as to prevent disturbing light from filtering through to the inside.

When the item 100 moves from the inspection position, the flexible bristles re-acquire their original shape thanks to the elasticity thereof, so as to be able to receive the next item 100.

This latter particular enables the device 1 to work with items 100 having different shapes and sizes, without there being any need to make structural modifications to the device 1.

As the brushes 43, 44 are in a fixed position with respect to the lamps 30, they are constantly subjected to very high temperatures which can cause damage to them, for example melting their flexible bristles.

To prevent this from happening, in the invention the linear brushes 43, 44 are associated to a cooling system. In the illustrated embodiment, the support blocks 46 of each brush 43, 44 are provided with a plurality of dispensing nozzles 48, singly destined to dispense a jet of a suitable cooling fluid, for example a micronised liquid or simply a jet of air, onto the flexible bristles

(see figure 4).

The dispensing nozzles 48 are orientated upwards and are located at the top of the support blocks 46, distributed in three parallel rows along the longitudinal development of the support blocks 46.

The rows of nozzles 48 are alternated with the lines 47 of flexible bristles. In particular, two rows of nozzles 48 are arranged adjacent to the external flanks of the lines 47, while the third row is arranged internally of the space which separates the lines 47. In this way, the jets of cooling fluid generated by the nozzles 48 are destined to strike the flanks of both lines 47 of flexible bristles, dissipating the excess heat. The dispensing nozzles 48 originate from a same manifold 49, which is afforded in the relative block 46 and is in turn connected to a supply system of the cooling fluid (not illustrated) located at a distance. It is observed that each linear brush 43, 44 might be provided with a single line 47 of flexible bristles, as long as the line 47 is sufficiently thick and closely packed to prevent the light from passing.

In this case, the cooling system would comprise, for each linear brush 43, 44, two parallel rows of dispensing nozzles 48, arranged on opposite sides of the single line 47 of flexible bristles. A second variant of the first embodiment of the invention is illustrated in figures 5 and 6.

In this variant the corridor 45 interposed between the collimator 40 and the sliding belts 20 is delimited by a frame formed by the transversal brushes 44 and by two identical disc brushes 50. The disc brushes 50 have a central axis A which is horizontal and perpendicular to the advancement path of the vegetable items 100 in the inspection position, and the disc brushes 50 are oppositely-facing on opposite sides with respect to the inlet 39 of the collimator 40. Each disc brush 50 comprises a central support element 51 , on which a plurality of flexible and elastic bristles are radially arranged (see figure 8). The flexible bristles of the plurality are distributed in order to form a crown 52 about the central support element 51 and are sufficiently thick to prevent the light from filtering through. Each disc brush 50 is rotatable mounted idle on a relative support organ fixed to the screen 41 , such as to be free to rotate about the central axis A thereof. The maximum diameter of the disc brushes 50 and the height at which they are located are such that the crowns 52 of flexible bristles partially project above the advancement plane of the items 100 defined by the sliding belts 20, such as to be destined to come into contact with the items 100 which transit from the inspection position.

In this way, apart from adapting to the shape of the items 100 in transit, the disc brushes 50 are destined to rotate about the central axis thereof, drawn by each item 100 which transits from the inspection position. Thanks to this rotation, the dragging between the flexible bristles of the disc brushes 50 and the items 100 is significantly reduced, also reducing the wear the disc brushes 50 and the items 100 are subject to. Further, this rotation is such that the bristles of the disc brushes 50 are overall less exposed to the rays of light emitted by the halogen lamps 30, and are thus more protected from any damage due to heat. In this case too it is possible to create a double barrier against the passage of disturbing light, by providing each disc brush 50 with two lines of flexible bristles defining two coaxial crowns 52 separated by a space.

Figures 7 and 8 illustrate a variant which enables a reduction of the overall sizes of the device, due to the disc brushes 50, while preserving the advantages thereof. In the above-mentioned variant, each disc brush 50 is substituted by a row of identical disc brushes 53, structurally the same as the preceding brushes but having a generally smaller diameter.

In particular, the disc brushes 53 have central axes B which are horizontal and parallel to the advancement path of the items 100; and they have rows 54 of flexible and elastic bristles which project partially above the defined sliding plane of the sliding belts 20, and are rotatably mounted on a support element fixed to the screen 41 such as to be free to rotate about the central axis B thereof.

The disc brushes 53 of each row have central axes B which are distinct and parallel, and are located side-by-side along the advancement path of the items 100 of vegetables.

To realise an adequate barrier against disturbing light without one interfering with the other during rotation, the disc brushes 53 of each row are reciprocally staggered in plan view, the respective crowns 54 of flexible bristles being superposed in a longitudinal direction. In this case too a double barrier can be created against the passage of disturbing light, by providing each disc brush 53 with two rows of flexible bristles which define two coaxial crowns 54 separated by a space. Figures 9 to 11 illustrate a further variant of the first embodiment of the invention.

In this further variant the sliding belts 20 of the continuous conveyor 2 are replaced by two parallel sliding linear brushes 60, which are contemporaneously destined to restingly support each item 100 to be inspected and are destined to slide constantly at the same speed, activated by a same motor group (not illustrated as of known type). Each sliding brush 60 comprises a sliding belt 61 to which a plurality of upwardly-projecting flexible and elastic bristles is fixed. The flexible bristles of the plurality are distributed along the whole longitudinal development of the relative belt 61 and are sufficiently thick as to prevent the light from passing.

In this way, at the inspection position, the sliding brushes 60 and the fixed transversal brushes 44 again define a frame which surrounds the inlet 39 of the collimator 40, delimiting a dark vertical corridor 45.

As in this case the flexible bristles develop only above the sliding plane of the items 100 defined by the sliding belts 61 , the sliding belts 61 are associated to guide rails 21 ' which develop vertically up until they rest on the protection screen 41 , such as to laterally close the corridor 45. In this variant, the items 100 to be inspected are loaded directly on the sliding brushes 60 and are made to advance by the brushes 60. In this way, the flexible bristles of the sliding brushes 60 adapt to the shape and size of the products 100 and advance together there-with, eliminating any reciprocal dragging. Further the heating of the flexible bristles of the sliding brushes 60 is drastically reduced, as only the tract thereof which is at the inspection position is exposed to the light rays emitted by the halogen lamps 30. The sliding linear brushes 60 are the relative guide rails 21' are preferably associated to means for adjusting (not illustrated) for varying the reciprocal distance according to the dimension and/or shape of the items 100 to be inspected. To improve the effectiveness of the sliding linear brushes 60, each sliding belt 61 is provided with two distinct rows of flexible bristles, respectively 62 and 63.

Each row 62, 63 comprises a plurality of adjacent flexible bristles which are distributed in such order as substantially to form a continuous wall along the longitudinal development of the relative sliding belt 61. In particular, each sliding belt 61 comprises a first row 63 of flexible bristles inclined from the bottom upwards towards the opposite sliding belt 61 , and a second row 62 of flexible bristles inclined from the bottom upwards in the opposite direction.

In this way, the first and second rows 62, 63 of flexible bristles are reciprocally opened out in an upwards direction, giving the sliding linear brushes 60 a substantially V-shaped transversal section. This particular conformation improves the stability of the transport of the items 100 to be inspected, and makes the barrier offered by the linear brushes 60 against the passage of the disturbing light more efficient. In the second embodiment, the inspection device 101 comprises a continuous conveyor 102, which uninterruptedly advances a sequence of items 100 of vegetables along a predetermined path, causing them to pass one at a time into a predetermined inspection position. The conveyor 102 can be of any known type.

In the illustrated example, the conveyor 102 is a usual sliding conveyor belt having a sufficient width for restingly supporting each item 100. Projector means 103 are installed at the inspection position, which project a concentrated beam F of high-intensity light onto each item 100 (figure 2). in particular, the projector means 103 function continuously and are destined to constantly project the concentrated beam F towards the inspection position, such as to illuminate each item 100 transiting through the position for a short time. The concentrated light beam F is calibrated such as to illuminate a limited portion of the external surface of the item 100 which is in the inspection position, such as to reduce the quantity of dispersed light to a minimum. The expression "dispersed light" relates to both the portion of light which is reflected from the vegetable item 100 and the portion of light which is diffused by the projector means 103 freely into the environment surrounding the inspection position. In order to achieve this objective, the concentrated beam F is preferably calibrated so that the breadth of the illuminated portion of the surface of the vegetable item 100 does not exceed about 20 mm. Alternatively or in addition to this, the concentrated beam F can be calibrated so that the breadth of the illuminated portion does not exceed 30% of the total area of the surface of the vegetable item 100. Means for receiving 104 are further installed at the inspection position, which means for receiving 104 receive at least a part of the light refracted from each item 100 following exposition to a concentrated beam F. The means for receiving 104 are associated to means for transmitting 105 for transmitting the captured portion of light towards a spectroscope located at a distance (not illustrated), which performs a spectroscopic analysis of the light in order to detect internal qualitative characteristics of the item 100.

In the illustrated example, the means for transmitting 105 comprise an optic fibre which connects the means for receiving 104 to the spectroscope. The means for receiving 104 are positioned on the opposite part of the projector means 103 with respect to the item 100 in the inspection position. In this way, the item 100 in the inspection position places the means for receiving 104 in shadow with respect to the concentrated light beam F, protecting both the direct light coming from the projector means 103 and the majority of the light reflected from the item 100 itself.

This preferred spatial arrangement, together with the choice of illuminating only a small portion of the surface of the item 100, guarantees that the means for receiving 104 can substantially capture only refracted light and thus makes the use of further protection means superfluous. In more detail the projector means 103 comprise a plurality of light sources 130 located by the side of the conveyor 102, which emit high-intensity light rays towards a same optical device 131 , which is interposed between the light sources 130 and the item 100 in the inspection position.

This optical device 131 concentrates the light rays coming from the light source 130 such as to form the above-mentioned concentrated light beam F, and directs the concentrated light beam F horizontally towards the vegetable item 100 in the inspection position.

In the illustrated example the light sources 130 are high-powered halogen lamps.

The halogen lamps 130 are fixed to a same support 132, on which they are distributed in the direction of the longitudinal development of the conveyor

102 and are arranged such as to project light rays concentrically towards the optical device 131.

In particular, the optical device 131 comprises a single condenser lens 131 '.

The condenser lens 131' is a flat-convex lens arranged with the convexity thereof facing towards the part of the item 100 which is in the inspection position.

The flat-convex condenser lens 131' is positioned such that the optical axis thereof crosses the centre of the item 100 in the inspection position, and such that the focal point thereof falls internally of the item 100 itself, preferably at about 20mm from the external surface thereof.

In particular, a flat-convex condenser lens 131' can be used which has a diameter of about 40mm with the focal point at about 15mm from the external surface of the item 100 in the inspection position.

The means for receiving 104 comprise a sensor, usually known as a collimator 140, which captures at least a portion of the refracted light from the item 100 in the inspection position, such as to make it available to the spectroscope located at distance.

The collimator 140 is a known instrument in the sector of inspection devices and can be realised in various constructive forms, according to need. In the illustrated example, it simply comprises a cylindrical tubular body which is orientated horizontally such that the central axis A' thereof is aligned to the propagation direction of the concentrated light beam F generated by the projector means 3 (see figure 2).

The optic fibre 105 is threaded into the cylindrical tubular body, which optic fibre 105 exits from the posterior end of the collimator 140 and is connected to the distance-located spectroscope.

The front end 141 of the cylindrical tubular body faces towards the vegetable item 100 which is in the inspection position and is closed by a transparent slide which protects the end of the optic fibre 105 located internally of the collimator 140 from extraneous material which might dirty it and obstruct it. In this way, the portion of refracted light which enters the collimator 140 through the front end 141 of the tubular body is conveyed to the internal end of the optical fibre 105, which transmits the light towards the spectroscope. Obviously, if the dimensions of the inspection device 1 allow it, the spectroscope can be directly connected to the collimator 140 without any interposing of any optic fibre.

In this case, the collimator 140 also functions as a means for transmitting the refracted light towards the spectroscope.

In a variant illustrated in figures 14 and 15, the means for receiving 104 further comprise an optical device 142 interposed between the vegetable item 100 in the inspection position and the collimator 140.

The optical device 142 is destined to be invested by a portion of the refracted light from the item 100 and concentrates the portion of light such as to form a concentrated beam G which enters the collimator 140 and strikes the internal end of the optic fibre 105 (see figure 15). The concentrated beam G possesses greater energy than the light which freely enters internally of the collimator 140, making transmission thereof through the optic fibre 105 more efficient, and the spectroscopic analysis more precise. In the illustrated example the optic device 142 comprises a single condenser lens 142'.

The condenser lens 142' is a flat-convex lens arranged with the convexity thereof facing the collimator 140. The flat-convex condenser lens 142' is positioned such that the optical axis thereof crosses both the item 100 in the inspection position and the initial tract of the optic fibre 105.

The optical axis of the condenser lens 142' coincides with the optical axis of the condenser lens 131' which is on the opposite side of the vegetable item 100.

Further, the focal point of the condenser lens 142' falls exactly at the end of the optic fibre 105. In this case too a flat-convex condenser lens 142' having a diameter of about 40mm can be used, with focal point about 35mm from the flat surface of the lens, and position the lens 42' about 15mm from the end of the optic fibre 105.

In a further variant, illustrated in figures 16 and 17, the projector means 103 and the means for receiving 104 are contained internally of a same closed casing 106 which defines a chamber which is light-isolated from the outside. The closed casing 106 prevents the environmental light from entering the isolated chamber, internally of which there is only the light produced by the projector means 103 and the light refracted from the vegetable item 100. In this way, the collimator is prevented from accidentally capturing environmental light which, otherwise, might alter the result of the spectroscopic analysis.

As illustrated in the figures of the drawings, the closed casing 106 is crossed by the conveyor belt 102 which enables each item 100 to transit from the inspection position internally of the isolated chamber. In particular, the items 100 enter and exit the isolated chamber by passing through two openable walls 160 of the closed casing 106. Each of the openable walls 160 can be formed for example by a plurality of elastic brittles that are sufficiently thick to prevent light from entering, and sufficiently flexible to displace as a passage curtain for the vegetable items 100.

Claims

1). A device for quality inspection of items (100) of fruit and vegetable produce, comprising: means for sequentially locating vegetable items (100) to be inspected in a predetermined inspection position along a predetermined path which path comprises the predetermined inspection position; means for illuminating (3) for projecting light rays on an item (100) of the items which is in the inspection position; and a sensor organ (40) which captures at least a portion of light refracted from the item (100) following an exposition thereof to the light rays, and which transmits the portion of refracted light to a spectroscope, the sensor organ (40) being located vertically below the item (100) of vegetable produce in the inspection position, characterised in that it comprises means for guiding at least a part of the light refracted to the sensor organ, which means for guiding are at least partly independent of a conveyor of the items (100).

2). The device of claim 1 , characterised in that the means for guiding at least a part of the refracted light to the sensor organ comprise an assembly of elastic walls (43, 44, 50, 53, 60) which surround the sensor organ (40) and which define a vertical corridor (45), which vertical corridor (45) guides at least a portion of the refracted light from the item (100) in the inspection position towards the sensor organ (40), the elastic walls (43, 44, 50, 53, 60) projecting above the advancement plane defined by the conveyor (2) and adhering to a surface of the item (100) which is in the inspection position, such that the item (100) superiorly closes the vertical corridor (45). 3). The device of claim 1 , characterised in that the means for guiding at least a part of the refracted light to the sensor organ (40) comprise a concentrating device for concentrating the refracted light such as to obtain a concentrated beam (G). 4) The device of claim 3, characterised in that the concentrating device comprises a condenser lens (142').

5). The device of claim 1 , characterised in that the conveyor (2) is a continuous conveyor. 6). The device of claim 5, characterised in that the conveyor (2) comprises two sliding belts (20) arranged parallel and on opposite sides of the sensor organ (40), which two sliding belts (20) contemporaneously restingly receive the products (100) to be inspected such as to advance them along the predetermined path. 7). The device of claim 2, characterised in that the assembly of elastic walls comprises two linearly-developing brushes (43) arranged parallel to the advancement path of the items (100) at the inspection position and positioned respectively on opposite sides of the sensor organ (40). 8). The device of claim 7, characterised in that the linearly-developing brushes (43) comprise a plurality of rows (47) of bristles, which bristles are reciprocally separated by a space.

9). The device of claim 7, characterised in that the assembly of elastic walls comprises two linearly-developing brushes (44) arranged transversally with respect to the advancement path of the items (100) at the inspection position and positioned respectively upstream and downstream of the sensor organ (40).

10). The device of claim 9, characterised in that the linearly-developing brushes (44) comprise a plurality of rows (47) of bristles which are reciprocally separated by a space. 11). The device of claim 2, characterised in that the assembly of elastic walls comprises at least two disc-shaped rotating brushes (50, 53) having rotation axes (A) which are perpendicular to the advancement path of the items (100) in the inspection position, the disc-shaped rotating brushes (50, 53) being positioned on opposite sides of the sensor organ (40). 12). The device of claim 11 , characterised in that the assembly of elastic walls comprises at least two rows of disc-shaped rotating brushes (53), each of which has a rotation axis (B) which is perpendicular to the advancement path of the items (10) in the inspection position, the disc-shaped rotating brushes (53) of each row being arranged adjacent along the advancement path of the items (100), the rows of disc-shaped rotating brushes (53) being positioned on opposite sides of the means for receiving. 13). The device of claim 11 , characterised in that each of the disc-shaped rotating brushes (50, 53) comprises a plurality of bristles which are reciprocally separated by a space.

14). The device of claim 2, characterised in that the assembly of elastic walls comprises two linearly-developing sliding brushes (60) arranged parallel on opposite sides of the sensor organ (40), which linearly-developing sliding brushes (60) contemporaneously restingly receive the items (100) to be inspected in order to advance the items (100) along the predetermined path.

15). The device of claim 14, characterised in that each sliding brush (60) comprises a sliding belt (61 ) and a plurality (62, 63) of bristles projecting upwards from the sliding belt (61 ) and distributed along a whole longitudinal development thereof.

16). The device of claim 15, characterised in that each sliding belt (60) comprises two distinct rows of bristles (62, 63) reciprocally facing upwards and directed at parted angles. 17). The device of claim 2, characterised in that it comprises means for cooling (48, 49) the assembly of elastic walls, which means for cooling direct jets of a cooling fluid onto the assembly of elastic walls.

18). The device of claim 1 , characterised in that it comprises means for receiving (104) for capturing at least a part of the light refracted internally of the item (100), and means for transmitting (105) for transmitting the part of refracted light to an instrument for spectrographic analysis.

19). The device of claim 18, characterised in that the means for receiving

(104) and the projector means (103) are located on opposite sides of the item

(100) which is in the inspection position. 20). The device of claim 18, characterised in that the means for receiving

(104) comprise a concentrator device (142) which concentrates the refracted light such as to obtain a concentrated beam (G) of light. 21 ). The device of claim 20, characterised in that the concentrator device

(142) comprises a condenser lens (142').

22). The device of claim 18, characterised in that it comprises projector means (103) for projecting a concentrated beam of light (F) onto a limited portion of an external surface of the item (100) which is in the inspection position.

23). The device of claim 22, characterised in that a maximum width of the limited portion of the external surface of the vegetable item (100) is about

20mm. 24). The device of claim 22, characterised in that a maximum width of the limited portion of the external surface of the vegetable item (100) is about

30% of the external surface of the vegetable item (100).

25). The device of claim 22, characterised in that the projector means (103) comprise at least a light source (130) which emits light rays towards a concentrator device (131), which concentrator device (131) concentrates the light rays such as to obtained the concentrated beam (F).

26). The device of claim 25, characterised in that the concentrator device

(131 ) comprises a condenser lens (131 ').

27). The device of claim 25, characterised in that the projector means (103) comprise a plurality of light sources (130) which emit light rays towards the concentrator device (131) .

28). The device of claim 27, characterised in that each of the light sources

(130) is a lamp.

29). The device of claim 27, characterised in that the concentrator device (142) comprises a condenser lens (142').

30). The device of claim 18, characterised in that the means for transmitting

(105) comprise an optic fibre.

31 ). The device of claim 18, characterised in that the projector means (103) and the means for receiving (104) are contained internally of a same chamber, which chamber is isolated from light from outside.

32). The device of claim 1 , characterised in that the means for locating an item (100) in a predetermined inspection position comprise a conveyor (102) which sequentially advances a plurality of items (100) along a predetermined path, which path comprises the inspection position.

33). The device of claim 1 , characterised in that the means for illuminating (3) are associated to means for positioning (31 , 32) which vary a direction of the emitted light rays, such as to place an area surrounding the inspection position in shadow.

34). A method for inspecting a quality of vegetable produce, characterised in that it comprises operating stages of: projecting at least a concentrated light beam (F) onto at least a portion of external surface of an item (100) of fruit or vegetable produce, by means of a sensor organ, capturing at least a part of the concentrated light beam (F) which is refracted internally of the item (100), guiding the at least a part of the concentrated light beam (F) which is refracted to an instrument for spectrographic wave analysis, protecting the part of refracted light from pollution from ambient light.

35). The method of claim 34, characterised in that the light beam (F) is concentrated on a limited area of a surface of the item (100) of vegetable produce.

36). The method of claim 34, characterised in that the guiding operation comprises delimiting and circumscribing the at least a part of refracted light internally of an assembly of elastic walls which define a vertical corridor between the vegetable product and the sensor organ.

37). The method of claim 35, characterised in that a widest span of the at least a part of the external surface of the item (100) of vegetable produce is about 20mm.

38). The method of claim 35, characterised in that the widest span of the at least a part of the external surface of the item (100) of vegetable product is about 30% of the external surface of the item (100).

39). The method of claim 35, characterised in that a projection of the concentrated light beam (F) comprises a stage of concentrating, via a concentrator device (131 ), light rays emitted by at least a light source (130). 40). The method of claim 39, characterised in that light rays emitted by a plurality of distinct light sources are concentrated through the concentrator device (131 ).

41 ). The method of claim 40, characterised in that the concentrator device (131 ) comprises a condenser lens (131 ').

42). The method of claim 34, characterised in that capturing the refracted light is done from an opposite side of the item (100) of vegetable produce with respect to the concentrated light beam (F).

43). The method of claim 34, characterised in that the capturing of the refracted light comprises a stage of concentrating the refracted light through a concentrator device (142) before transmitting the refracted light to the instrument for spectroscopic analysis.

44). The method of claim 43, characterised in that the concentrator device

(142) comprises a condenser lens (142'). 45). The method of claim 34, characterised in that transmission of the refracted light to the instrument for spectrographic analysis is done through an optic fibre (105).

46). The method of claim 34, characterised in that the method includes performing the stages of projecting the concentrated light beam (F) and capturing the at least a part of refracted light internally of a chamber which is isolated in terms of light from an outside environment.

47). The method of claim 34, characterised in that a plurality of items (100) of fruit or vegetable produce are advanced in sequence along a predetermined path, and are made to pass one at a time through an inspection position in which each item (100) is subjected to the operating stages.