Field of the Invention.

The present invention relates to grading and packing fruit and in particular for post-harvest grading and packing of bananas.

Background Art.

After fruit are picked or harvested, the fruit are typically graded as the different quality grades of fruit fetch different sums or may be directed to different markets.

Once graded, the fruit are separated into graded batches and a packaged for transport.

The grading and packaging of fruit is conventionally performed by humans. For example, the grading step normally involves the picked fruit passing in front of a human grader and the human operator will normally grade the fruit using their eye and experience.

The apparatus used is similar to a conveyor belt but instead of a simple belt moving laterally, this fruit conveyor belt has a portion divided into sections with each fruit located in a section. As the conveyor travels laterally carrying the fruit, the fruit also rotate such that the human operator can see substantially all portions of the fruit.

As well as grading the fruit as they pass, the human operator may reject fruit for any one of a variety of reasons including that the fruit is not ripe enough or likely to ripen enough, or that the fruit is too damaged to sell.

Once graded, the fruit are then typically packed into packages containing multiple fruit in support trays to minimize any damage to the fruit. The packages also have identifying indicia applied to the exterior to indicate the origin of the fruit, their grade and their picking and/or packaging date.

Bananas have particular problems in grading and packaging as they are picked in bunches known as "hands" with each banana referred to as a "finger". As is well known, bananas are non-spheroidal and therefore do not roll well if at all. This means that the above described lateral transfer and rotating conveyor cannot be used for bananas.

In the art, bananas are typically graded and packaged by hand. This means that the operators used must all have substantial experience in grading the fruit (as opposed to a much smaller number of operators which can be used to grade spherical fruit using the conveyor system) and also that the grading and packaging of bananas is a time consuming and physically draining job. Even so, the grading of bananas in this manner has proceeded with high quality standards.

It would therefore be a clear advance in the art to provide a more automated system for grading and packaging fruit, and in particular bananas, to minimize the time spent grading whilst maintaining quality standards.

It will be clearly understood that, if a prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country.

Summary of the Invention.

The present invention is directed to a process and apparatus for grading and packing fruit, which may at least partially overcome at least one of the abovementioned disadvantages or provide the consumer with a useful or commercial choice.

With the foregoing in view, the present invention in one form, resides broadly in a process for grading and packing produce including the steps of:

a) Separating the produce into single units;

b) imaging each single unit to ascertain its sorting characteristics including at least quality grade and size;

c) applying sorting identification indicia to the exterior of the single unit based on the imaging; and

d) packing the produce into a package based on the quality grade and size, with each package containing a plurality of single units of the same quality grade and a similar size.

In another form, the invention resides broadly in a grading and packing line for grading and packing produce including:

a) a separating and loading apparatus for separating the produce into single units and loading the single units onto a conveyor;

b) an alignment apparatus to align the units such that a stem portion of each single unit is oriented in the same direction; c) an optical imaging system to collect at least one image of each single unit to ascertain sorting characteristics including at least quality grade and size by comparison to a database of standard quality characteristics;

d) an application apparatus to apply identification indicia to the exterior of the single unit based on at least one of the sorting characteristics of each single unit; and

e) a packing apparatus to package the single unit based on the quality grade and size of the unit, with each package containing a plurality of single unit of the same quality grade and a similar size.

In a further form, the present invention resides broadly in a process for grading and packing produce including the steps of:

a. imaging a plurality of single unit to ascertain sorting characteristics including at least quality grade and size for each;

b. applying sorting identification indicia to the exterior of the single unit based on the imaging; and

c. packing the produce into a package based on the quality grade and size, with each package containing a plurality of single unit of the same quality grade and a similar size.

In still another form, the invention resides broadly in a grading and packing line for grading and packing produce including:

a. a loading apparatus for loading single units onto a conveyor;

b. an alignment apparatus to align the unit such that a stem portion of each single unit is oriented in the same direction;

c. an optical imaging system to collect at least one image of each single unit to ascertain sorting characteristics including at least quality grade and size by comparison to a database of standard quality characteristics;

d. an application apparatus to apply identification indicia to the exterior of the single unit based on at least one of the sorting characteristics of each single unit; and

e. a packing apparatus to package the single unit based on the quality grade and size of the unit, with each package containing a plurality of single unit of the same quality grade and a similar size. Whilst the process and apparatus of the present invention are particularly directed to the grading and packaging of fruit such as bananas, it can be used for any fruit or vegetable. It can also be easily adapted to automated grading and packaging of any foodstuff such as meat for example. The invention will be describes with particular reference to fruit.

The grading is preferably accomplished through an optical mechanism of capturing at least one image of the fruit and comparing the at least one image to one or more control images to establish a grade based on the comparison.

The fruit will then typically be packaged according to grade firstly and then according to size. It is further preferred that other attributes such as shape may be used to classify the fruit. There may be a feedback system which checks the package containing the fruit for compliance with a particular test parameter such as package weight of above a particular threshold. For example, a punnet containing six bananas may require a minimum weight of 800 g before passing.

The process typically includes the step of separating the fruit into single fruit. When using bananas as the example of the fruit, it is known that bananas are typically picked or harvested in bunches, each weighing up to 60kg with a central stem portion supporting numerous "hands" of between 4 and 10 banana "fingers".

The fingers may be separate (this is unlikely) but if not, a separating apparatus will preferably be provided to separate the bunches and hands into individual fingers for processing.

The separating step may include a sub-step of loading the fingers onto a conveying means, typically a conveyor belt or similar in order to pass the bananas through the imaging and application steps.

Normally, the fingers will be randomly loaded and they may accordingly, have a number of different orientations. It is important for the purposes of the present invention that the fingers are oriented the same way.

Therefore, orientation means may be provided. The orientation means may include one or more angled portions, such as a plate, angled to lift and orient the bananas as the conveyor transports the bananas laterally. The conveyor will therefore normally provide the longitudinal force, pressing the bananas against the angled orientation plate as they are being transported. Preferably, the orientation means will orient the bananas such that all bananas are oriented with their stem portions toward a single lateral side of the conveyor so that all bananas start the imaging step in the same orientation.

The separating step may be manual but an automatic means is preferred. As an example, the manual separation and loading of the bananas would normally take approximately 5-10 seconds per hand.

One example of an automated separation of hands of bananas into single fingers is to provide a number of chutes or similar for the bananas to pass through tip first with cutting blades provided on a forward portion of the chute wall to separate the stems. The chutes will normally be oriented parallel to the direction of travel and will normally be sized to receive a single banana only.

The fruit may also be washed prior to entry into the classification area. For example, fruit may be floated out of wash tanks without the need for labour.

The process also includes the step of imaging each single fruit to ascertain its sorting characteristics including at least quality grade and size.

The single fruit will preferably each be imaged from a fixed reference point above or beside the conveyor. Normally, the bananas will move relative, normally longitudinally, to the imaging means on the conveyor. The conveyor may be coloured in order to provide contrast with the fruit. White or another light colour may be used for this purpose however light colours tend to create "flashing" problems so a dark colour, such as black is preferred.

The imaging may alternatively take place with the imaging means using a moving reference in order to image each fruit for a longer period, but this will typically not be required.

An imaging apparatus that can move longitudinally with the conveyor may be used.

There will typically be more than one imaging apparatus provided. Typically, a first side of the fruit will be imaged with the fruit enters the imaging step in a particular orientation, the fruit will then be re-oriented and at least a second side of the fruit will be imaged before the fruit is returned to the orientation in which it entered the imaging step.

The orientation changing means may be the same as that used prior to imaging to orient the fruit. Alternatively and more preferred is that the orientation change may be accomplished by providing a change in elevation in the conveyor. Preferably, a pair of conveyors will be provided in sequence in the imaging step, one associated with each imaging means and with the first conveyor feeding the fruit onto the second conveyor. By mounting the first conveyor at a higher level than the second conveyor, the fruit will fall a small distance off the first conveyor onto the second conveyor. During the small fall, the fruit will generally rotate to another side, exposing a different side to the second imaging means.

Alternatively, an overhead, gentle sweep device may be used in order to realign the fruit. An example of a sweep device may be fingers extending downwardly such that as the fruit passes the fingers, a portion of the fruit will abut the finger, rotating the fruit as the conveyor moves the fruit past the finger.

Each imaging means will preferably provide between 90°- 120° view of the fruit from any one side. The viewing angle of the imaging means will normally determine the number of imaging means used.

The imaging means may move laterally across the conveyor or vertically if side mounted. This type of imaging means may also be mounted for reciprocal movement. The path of movement may be an arcuate path. The imaging means may be mounted to move in a single plane but to pivot as it traverses thereby increasing the viewing angle of the imaging means.

Alternatively, the imaging means may be mounted on a carriage that travels on an arcuate path.

Each imaging means will typically be located in a shielded area in order to reduce the variables that are encountered during imaging which in turn may reduce its consistency. One variable may be natural lighting and artificial lighting may be provided particularly within the shielded areas.

Preferably, the imager captures a variety of features including the length, the degree of curvature or other aesthetic parameter, the girth and the quality of each fruit. Normally, the physical size parameters of the fruit will be measured relative to a scale or similar. A reference scale may be provided on the conveyor for example or on the background to establish the size of each fruit.

An imaging device may also be used prior to the analysis in order to determine the orientation of individual fruit. For example, a two position diverter may be used to orient individual fruit which might not be in a conforming orientation. It is preferred that the fruit travel with their stems trailing. A virtual reference scale may be used alternatively for example using the focal length of the imaging means.

The quality of each single fruit will typically be determined by comparing one or more images which are captured to one or more control images stored in the system.

The sorting characteristics of each fruit will normally be indexed with a unique identifier so that the fruit can have the correct sorting identification indicia applied thereto.

This quality comparison will typically provide a number of triggers. First, an "accept/reject" decision may be made by the system based on the comparison whereby individual fruit are either accepted as meeting at least a minimum quality standard or rejected as not meeting the minimum standard.

Secondly, the comparison will give a "grade" to each fruit piece. This grading is preferably used during the packing step so that fruit of the same grade are packaged together.

Typically, the quality comparison will be governed by a comparison algorithm. The algorithm will normally compare aesthetic qualities such as colour, uniformity of colour, blemishes, degree of blemishing, deformations, uniformity of shape and closeness to aesthetic perfection and use any or all of these parameters (and/or others) as a basis for both the "accept/reject" decision and the quality decision.

The aesthetic qualities may be compared to the control aesthetic quality characteristics using any suitable comparison mechanism or system. For example, for characteristics such as uniformity of colour, degree of blemishing, uniformity of shape and closeness to aesthetic perfection, statistical methods may be used whereas for colour alone, comparison with appropriate colour chart may be used.

The comparison of the fruit may also result in a classification of fruit based on the shape, size and/or quality grade. The fruit may be separated into different classifications.

In still a further embodiment, the invention resides in an apparatus for determining at least one classification characteristic for fruits or vegetables, the apparatus including at least one imaging apparatus to at least temporarily capture at least one classification characteristic of each single fruit and a processing means to store one or more control classification characteristics and to compare captured at least one classification characteristic of each single fruit to the one or more control classification characteristics to ascertain at least quality grade and size grade for each single fruit.

In yet a further embodiment, the invention resides in a method for determining at least one classification characteristic for fruits or vegetables, the method including storing one or more control classification characteristics for a fruit or vegetable, at least temporarily capturing at least one classification characteristic of single fruit or vegetable using at least one imaging apparatus and comparing captured at least one classification characteristic of each fruit or vegetable to one or more control classification characteristics using a processing means and to ascertain at least quality grade and size grade for each fruit or vegetable.

The process also includes a step wherein sorting identification indicia are applied to the exterior of the single fruit based on the imaging. Typically, the indicia will be limited to quality information. The indicia will normally be applied to allow easy recognition for the consumer buying the fruit but may also assist with the packaging step allowing more simple identification of fruit of different grades.

Any form of indicia may be used. The indicium is typically applied to an exterior portion of the fruit which is visible but which will not be eaten by the consumer. The indicia may be of any form and may contain written or coded information such as a bar code for example, or the fruit may be "tipped".

"Tipping" involves applying a coating of contrasting colour to the tip or a bottom end of the fruit. Normally, different colours are used to indicate different grades of fruit. The colours chosen will preferably be contrasting with the colour of the fruit and therefore, for bananas, the colours typically include red, green and blue as examples. A clear or transparent coating may be used.

The coating may be applied using any method and normally up to a third of the length of the fruit. The method will normally be chosen according to the material used for the coating.

For bananas, a particularly preferred coating material is wax or similar, settable material. Wax is preferred because of its low melting point meaning that it can be applied without damaging the fruit. For other fruits and/or vegetables, more of the fruit or vegetable may be covered with a coating as different types of fruit or vegetable respond to a coating of greater or lesser extent.

The preferred method of application for wax is dipping but pouring or brushing may also be used.

If dipping, the fruit will normally have to be vertical for the dipping. This may mean that the fruit may have to be manipulated into the vertical orientation if not already. This may entail further handling which can damage the fruit. One preferred method for handling the fruit at this stage will be through suction. Preferably, the fruit remain as much as possible in the same orientation as when entering the imaging step. If pouring or brushing is used, the fruit can be in any orientation.

The coating may be achieved by grasping the fruit and moving the fruit to the coating source or moving the fruit past or through the coating source.

For the coating process, it is important that the fruit are all oriented in the same direction. Some re-orientation may be necessary but should be minimized.

The orientation of the fruit may be checked prior to coating, for example during imaging with incorrectly oriented fruit preferably returned for re-orientation before passing through the imaging step.

The process includes the step of packing the fruit into a package based on the quality grade and size, with each package containing a plurality of single fruit of the same quality grade and a similar size.

Typically, the fruit are packaged into groups of 6 fruit of the same grade and or a similar physical size. The package will normally be a punnet or carton or similar. Preferably, the packaging is foldable and the fruit will typically be placed on a blank, then the package folded about the fruit.

It is preferred that the package will display both the fruit but especially the indicia indicating the quality of the fruit.

It is preferred that the apparatus according to the present invention is provided in an L-shaped configuration such that the accept or reject decision can be made at the corner portion and any fruit which are rejected can simply proceed off the end of one of the arms with the quality inspection occurring on the perpendicular arm portion of the apparatus. The system of the present invention may also include human quality assurance or inspection at any stage or at more than one stage.

Brief Description of the Drawings.

Various embodiments of the invention will be described with reference to the following drawings, in which:

Figure 1 is a schematic flowchart illustrating the four main steps of a method according to a preferred embodiment of the present invention.

Figure 1 A is a photograph of an imaging step according to a preferred embodiment.

Figure IB is a photograph of a "tipping" step according to a preferred embodiment.

Figure 1 C is a photograph of a packaging step according to a preferred embodiment.

Figure 2 is a schematic flowchart illustrating the sub-steps of the loading step of a method according to a preferred embodiment of the present invention.

Figure 3 is a schematic flowchart illustrating the sub-steps of the imaging step of a method according to a preferred embodiment of the present invention.

Figure 4 is a schematic flowchart illustrating the sub-steps of the "tipping" step of a method according to a preferred embodiment of the present invention.

Figure 5 is a schematic flowchart illustrating the sub-steps of the packing and dispatch step of a method according to a preferred embodiment of the present invention.

Figure 6 illustrates a number of packages with bananas therein, graded and packed according to a preferred embodiment.

Detailed Description of the Preferred Embodiment.

In one preferred form, the present invention provides an apparatus of grading and packaging bananas which operates according to a particular method.

As illustrated schematically in Figures 1 to 1C, the apparatus is a grading and packing line for grading and packing fruit. The line includes: a. a loading apparatus (not shown as this embodiment has the bananas loaded by hand) for loading single fruit onto a conveyor;

b. an optical imaging system, illustrated in Figure 1A, to collect at least one image of each single fruit to ascertain sorting characteristics including at least quality grade and size by comparison to a database of standard quality characteristics;

c. an application apparatus, illustrated in Figure IB, to apply identification indicia to the exterior of the single fruit based on at least one of the sorting characteristics of each single fruit; and

d. a packing apparatus, illustrated in Figure 1C, to package the single fruit based on the quality grade and size of the fruit, with each package containing a plurality of single fruit of the same quality grade and a similar size.

The process and apparatus of the illustrated embodiment is particularly directed to the grading and packaging of bananas.

The grading is accomplished through an optical mechanism of capturing images of the fruit and comparing the captured images to one or more control images to establish a grade based on the comparison. The fruit are then packaged according to grade firstly and then according to size.

The process illustrated includes the step of separating the fruit into single fruit although this step has been accomplished by hand in the illustrated embodiment. Bananas are picked or harvested in bunches, each weighing up to 60kg with a central stem portion supporting numerous "hands" of between 4 and 10 banana "fingers".

The process includes the step of imaging each single fruit to ascertain its sorting characteristics including at least quality grade and size. This step is illustrated in Figure 1 A and algorithmically in Figure 3.

The single fruit are imaged from a fixed reference point above the conveyor upon which the banana fingers are on. The bananas move longitudinally on the conveyor under an imaging means.

According to the embodiment illustrated in Figure 1A, there are two imaging apparatus provided. A first side of the fruit is imaged as the fruit enters the imaging step in a particular orientation, the fruit is then re-oriented and a second side of the fruit is imaged before the fruit is returned to the orientation in which it entered the imaging step.

The orientation change is accomplished in the illustrated embodiment by providing a change in elevation in the conveyor. A pair of conveyors 10 and 12 are provided in sequence in the imaging step, one associated with each imaging means 11 and 13 and with the first conveyor 10 feeding the fruit onto the second conveyor 12. By mounting the first conveyor 10 at a higher level than the second conveyor 12, the fruit will fall a small distance off the first conveyor 10 onto the second conveyor 12. During the small fall, the fruit will generally rotate to another side, exposing a different side to the second imaging means 13.

Each imaging means will preferably provide between 90°- 120° view of the fruit from any one side. The viewing angle of the imaging means will normally determine the number of imaging means used.

Each imaging means is located in a shielded area 14 in order to reduce the variables that are encountered during imaging which in turn may reduce consistency to the grading. One variable is natural lighting which is subject to variations and artificial lighting is provided particularly within the shielded areas 14.

Each imaging means captures a variety of features including the length, the degree of curvature or other aesthetic parameter, the girth and the quality of each fruit. Normally, the physical size parameters of the fruit will be measured relative to a scale or similar. A reference scale may be provided on the conveyor for example or on the background to establish the size of each fruit.

The quality of each single fruit is determined by comparing one or more images which are captured to one or more control images stored in the system. The sorting characteristics of each fruit are indexed with a unique identifier so that the fruit can have the correct sorting identification indicia applied thereto.

This quality comparison will typically provide a number of triggers. First, an "accept/reject" decision may be made by the system based on the comparison whereby individual fruit are either accepted as meeting at least a minimum quality standard or rejected as not meeting the minimum standard.

Secondly, the comparison will give a "grade" to each fruit piece. This grading is preferably used during the packing step so that fruit of the same grade are packaged together. Typically, the quality comparison will be governed by a comparison algorithm and implemented using a computer. The algorithm compares aesthetic qualities such as colour, uniformity of colour, blemishes, degree of blemishing, deformations, uniformity of shape and closeness to aesthetic perfection and use any or all of these parameters (and/or others) as a basis for both the "accept/reject" decision and the quality decision. According to the illustrated embodiment, there is a computerised comparison accomplished that each imaging means, and either imaging means and comparison may trigger will be "accept/reject" decision but it is preferably a combination of both comparisons that control the grading.

The process also includes a step wherein sorting identification indicia are applied to the exterior of the single fruit based on the imaging, as illustrated in Figure IB. Typically, the indicia are limited to quality information. The indicia will normally be applied to allow easy recognition for the consumer buying the fruit but may also assist with the packaging step allowing more simple identification of fruit of different grades.

The indicium preferred is applied to an exterior portion of the fruit which is visible but which will not be eaten by the consumer. According to the illustrated embodiment, the fruit are "tipped".

"Tipping" involves applying a coating of contrasting colour to the tip or a bottom end of the fruit. Normally, different colours are used to indicate different grades of fruit. The colours chosen contrast with the colour of the fruit and therefore, for bananas, the colours typically include red, green and blue as examples.

The coating may be applied using any method and normally up to a third of the length of the fruit. For bananas, a particularly preferred coating material is wax or similar, settable material. Wax is preferred due to its low melting point meaning that it can be applied without damaging the fruit.

The preferred method of application for wax is dipping which will normally occur directly after the grading is complete. For the coating process, it is important that the fruit are all oriented in the same direction thus placing the tipping apparatus directly after the imaging step is preferred as the bananas are still oriented the same direction at that stage.

As illustrated, the fruit will be vertical for the dipping. The fruit are therefore moved into the vertical orientation by grasping the banana using a controlled grasping means 15 and moving the fruit to the coating source 16, dipping and returning the dipped banana to the second conveyor 12.

The process also includes the step of packing the fruit into a package based on the quality grade and size, with each package containing a plurality of single fruit of the same quality grade and a similar size, as illustrated in Figure 1C.

Typically, the fruit are packaged into groups of 6 fruit of the same grade and or a similar physical size. The package, as illustrated in Figure 6, is a punnet or carton or similar foldable about the fruit, with the fruit placed on a blank 17, then the package folded about the fruit.

It is preferred that the package will display both the fruit but especially the indicia indicating the quality of the fruit as can be seen from Figure 6.

In the present specification and claims (if any), the word "comprising" and its derivatives including "comprises" and "comprise" include each of the stated integers but does not exclude the inclusion of one or more further integers.

Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations.