WO2016131109A1

WO2016131109A1 - System to monitor foodstuff cooking

Info

Publication number: WO2016131109A1
Application number: PCT/AU2016/050114
Authority: WO
Inventors: Paul Eaton Willett
Original assignee: Paul Eaton Willett
Priority date: 2015-02-20
Filing date: 2016-02-19
Publication date: 2016-08-25

Abstract

A method of cooking foodstuff in a heated cooking apparatus comprising the steps of: a) recording data of the radiation emissions or reflections from the foodstuff surface within the cooking apparatus on a receiver having a field of view covering at least the foodstuff surface; b) comparing the data with data indicative of a pre-set condition; c) providing an indication that the recorded data in at least part of the field of view is the same as the data indicative of a pre-set condition; and d) removing the foodstuff from the heated cooking apparatus.

Description

System to monitor foodstuff cooking

Field of the invention

This invention relates to cooking apparatus and in particular to a system and method to monitor the colour change of food during a cooking procedure.

Background of the invention

While the invention will be described with reference to grilling foodstuff under a griller, it is not restricted in scope to this application and is equally applicable to other types of cooking apparatus whether the food is supported on a stationary or continually moving platform.

Grilling or toasting is a common method of cooking, and the heat source can be from both sides of the food at once, or all from the bottom or the top of food as required for desired cook.

As an example of use of a griller in a commercial kitchen environment, it is a common procedure to place toppings on foods such as cheese on a lobster tail and then grill mostly the top of food until the cheese is browned to a desired colour and the lobster is heated through.

Because the heat is quite a bit higher than in baking, and often infrared, the grilling can be a hit and miss process due to the number of variables in the process. These variables include the temperature and moisture level of food or topping, the amount of topping and how evenly it is spread, the even-ness of the heat source doing the grilling and the sugar level of topping or food.

Food such as fish can have different densities of thickness throughout the food item, where the thinner areas will grill faster and therefore also colour darker and quicker than the thicker areas. It is found that the grilling or toasting of many foods can require very close and constant monitoring to avoid the product darkening or burning which consumes valuable time in a commercial kitchen or restaurant. The cost of damaged product and loss of custom from badly grilled product can also be considerable, with the cost of a grilling machine being less important than the need for time efficient processes and consistent quality. Therefore it is desirable that a less human resource method of supervising and/or monitoring the cooking of food is available to avoid unnecessary food damage.

Summary of the invention

According to one aspect of the invention, there is provided a method of monitoring cooking of a foodstuff in an apparatus, the cooking apparatus comprising at least one heating element for applying a heat treatment to a cooking position, at least one food conveyance upon which the foodstuff is positioned and a data receiver having a field of vision covering an inspection position comprising the steps of ;

(a) loading a foodstuff onto the at least one food conveyance and selecting a preprogrammed cooking cycle

(b) recording data of the foodstuff on the food conveyance when the food

conveyance is initially in the inspection position;

(c) moving the food conveyance into the cooking position to start the cooking time and subjecting the foodstuff to heat treatment for a period of time according to a pre-programmed cooking cycle;

(d) moving the food conveyance into the inspection position after the initial period of time specified by the pre-programmed cooking cycle and recording image data of the foodstuff;

(e) comparing the image data with known image data indicative of a pre-set cooked condition;

(f) determining an adjusted cooking time to reach the pre-set condition based on at least the current image data and elapsed cooking time since the start of cooking

(g) moving the food conveyance into the cooking position and subjecting the

foodstuff to heat treatment for the adjusted cooking time; and

(h) causing the foodstuff to be removed from the heat treatment after adjusted

cooking time.

In another aspect there is provided a system for monitoring the changes in the surface of a foodstuff in a heated cooking apparatus, the cooking apparatus comprising a cooking position and an inspection position, at least one heating element for applying a heat treatment to the cooking position, at least one food conveyance upon which the foodstuff is positioned and moved between the cooking position and inspection position, he system comprising:

a) and a data receiver having a field of view covering the inspection position being tbeing adapted to receive data of the radiation emitted or reflected from the surface of the foodstuff in the inspection position;

b) a processor communicating with the data receiver for receiving radiation data and determining whether the recorded data is indicative of the foodstuff reaching a pre-set condition, c) an actuator to move the foodstuff conveyance between the cooking position and inspection position so that the foodstuff can be inspected; and d) an alarm to indicate that the foodstuff has reached a pre-set condition.

In a further aspect there is provided a method of cooking foodstuff in a heated cooking apparatus, the cooking apparatus comprising at least one heating element for applying a heat treatment to a cooking position, at least one food conveyance upon which the foodstuff is positioned and a data receiver having a field of vision covering an inspection position, the method comprising the steps of:

a) moving the foodstuff on the food conveyance into an inspection position in the field of view of the data receiver; b) recording data of the radiation emissions or reflections from a surface of the foodstuff; c) determining whether the recorded data is indicative of the foodstuff reaching a pre-set condition; and either i) moving the foodstuff into the cooking position for further heat treatment if the condition has not been met; or ii) indicating that the foodstuff has reached a pre-set condition. The invention may also provide, an apparatus for cooking foodstuff comprising a) at least one food conveyance upon which foodstuff is positioned; the at least one conveyance being movable between an inspection position and a cooking position; b) at least one heating element over the cooking position of the at least one

foodstuff conveyance; c) a data receiver having a transmission window and a field of view including at least the foodstuff on the conveyance in the inspection position, the receiver being adapted for receiving image data of radiation or reflective emissions from the foodstuff surface; d) a processor communicating with the receiver for receiving image data and

comparing the data to stored data indicative of a pre-set cooking condition; e) a reference surface of known emissive or reflective values, in or movable to

within at least the field of view of the receiver to enable comparative emissive or reflective data to be collected from the reference surface and compared with stored reference data as an indication of whether the reference surface or transmission surface requires cleaning f) a cleaning arrangement to clean the transmission window or reference surface.

Another aspect provides a method of cooking foodstuff in a heated cooking apparatus the cooking apparatus comprising at least one heating element for applying a heat treatment to a cooking position, at least one food conveyance upon which the foodstuff is positioned and a data receiver having a field of vision covering an inspection position, the method comprising the steps of:

a) recording data of the emissions or reflective radiation on the data receiver from a known reference surface through the transmission window; b) comparing the data of emissions or reflective radiation from the known reference surface with known data of the reference surface; and c) initiating a cleaning procedure of the transmission window, if the data of emissions or reflective radiation recorded from the reference value varies from the known data.

In another aspect there is provided, a method of maintaining the accuracy of a monitoring system for foodstuff in a heated cooking apparatus, the monitoring system comprising a receiver having a transmission window directed at the foodstuff surface, the receiver having a field of view covering at least the foodstuff surface, the method including steps of:

a) recording data of the emissions or reflective radiation from a reference surface; b) comparing the data of emissions or reflective radiation from the known reference surface with known data of the reference surface; and c) initiating a cleaning procedure of the transmission window, if the data of emissions or reflective recorded in step (a) varies from the known data.

An air blower may be provided to minimise the amount of material contacting and potentially affecting the transmissibility of the window. This helps to blow fat and other debris away from the transmission window.

The transmission window may further be provided with a disposable surface liner having a replacement apparatus which replaces the surface liner when the data of emissions or surface radiation from the known reference surface differs outside if tolerance limits from the known data of the reference surface. The disposable surface preferably includes a continuous strip which rolls on at least the dimension of the window to replace the entire surface of covering the transmission window.

The method of maintaining the accuracy of the monitoring system may be done concurrently with the cooking method so that the accuracy of the monitoring system can be maintained.

Brief description of the drawings

Figure 1 is a plan view of an embodiment of the invention; Figure 2 is a plan view of the vision unit;

Figure 3 is pixilation data referring to 3 pieces of toast: (1 ) Plain bread, (2) Desired colour, (3) Outer edge of quality acceptability; and

Figure 4 is a flowchart of a cooking and monitoring process in accordance with the invention.

Detailed description of the embodiments

It will be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.

Figure 1 shows an embodiment of the invention. The design shown in Figure 1 is typical, but is not limited to this embodiment.

Figure 1 illustrates a cooking apparatus such as a griller or oven, having a grilling or baking chamber. Heating elements are provided at the top (3) of the chamber (13) as a bank of heating elements. Another bank of elements are provided at the bottom (4) and are preferably able to be switched independently depending on the evenness of the colour of the food being cooked.

The oven chamber may be a grilling machine which may be a vertical or horizontal open or closed grilling machine. It may also be in the form of a conveyor type grill or toaster, where the foods pass through from one end to exit at the other end after cooking. The food can be breads, cereals, meat, or dairy based or any other product that is grilled, broiled or baked to a required level.

The apparatus further comprises fully contained vision unit (12) comprising a housing which includes a radiation receiver such as a digital camera (16). The radiation receiver receives image data such as reflected or emitted radiation and converts it to digital data for analysis. The radiation is preferably of infra-red to visible light wavelengths. In most cases it will be detecting visible light as this is an indication of the colour of the food which goes to its appearance. Infrared radiation could also be used as an indication of the temperature of the food and it is more an indication of the progress through the cooking cycle.

The apparatus includes a food conveyance, shown as a product rack (2) upon which the food sits in the chamber. In the embodiment shown, the food is moved at predetermined intervals between the heating position under the heating elements and a monitoring position where the food is in the field of view of the radiation receiver (16). The product rack (2) holds the product being grilled or toasted, and this can be adjusted up or down relative to the top heating elements (3). A light source shines known light onto the monitoring position and image data is collected on the radiation being emitted or reflected from the food surface and the tray moved back into the heating element section of the chamber (13) once a reading has been taken.

The radiation receiver (16) may be a digital camera associated with a lens supported within housing 21 . The radiation receiver (16) is in communication with a processor (17) which receives data from the radiation receiver 16 and compares it to know reference data.

Fully contained vision unit (12) comprises housing 21 containing radiation receiver (16) at an optimum height of 450mm, a light source (18) in front of the radiation receiver(16) (closest to cooking appliance) projecting a constant light of known character onto the monitoring position, a spool mechanism (19) that will be able to roll a transparent surface liner which is preferably disposable, over the lens of the radiation receiver (16) and a cooling fan (14) associated with the insulated vision unit (12) protecting the components from the heat generated by the cooking appliance. The disposable surface liner is preferably a protective clear tape.

A fan (14) also provides an air curtain blown over the radiation receiver (16) and light (3), protecting the lens of the radiation receiver (16) from impurities such as smoke, steam, dust and grease from compromising data by gathering on lens and impeding data receivable. The fan (14) will also serve the purpose to protect the radiation receiver (16) from heat generated from cooking appliance.

The light source (18) will be one that is of even brightness that will maintain a constant, regulated even light so as to achieve a measured accuracy of signal and data. This can be measured and monitored by computer and registered as a fault if the measured light fluctuates over or above a desired brightness.

As a function of the vision unit (12), a protective cover (20) covers the lens of the radiation receiver (16) and is controlled to swing or slide away exposing the lens to receive data. This action may be initiated and is utilized in synchronous with the inwards and outwards movement of product rack (2) or can be operated independently with a device such as a solenoid.

A linear actuator (6) is provided to move the product rack (2) into and out of the chamber (13). This is situated at the side of the cooking appliance (1 ) and has an ejection distance of 300mm. A flap (9) is provided covering the opening between the heating position in the cooking chamber and the monitoring position (10). The flap (9) cooperates with the product rack 2 to cover the opening in the chamber (13) after the product rack has moved between the heating and monitoring position and back into the chamber (13). With the inward and outward movement of the product rack (2) to and from the cooking chamber (13), the flap (9) covering the opening to oven chamber (13) is withdrawn. When product rack (2) is drawn inwards, flap (9) will reengage or move back into the position to close off the top of oven chamber (13) keeping heat in and generally keeping smoke and steam away from the monitoring position and the radiation receiver (16). A background tray 10 is provided as part of the monitoring position. Once the conveyance has been returned to the oven chamber 13, the radiation receiver may monitor the condition of the background tray 10 against known reference data. A warning may activate when the image data of the background tray (10) is found to be outside a predetermined tolerance level indicating the background tray is dirty. The radiation receiver (16) needs to select the best spectrum for conducting these checks and check the background tray at intervals such as when product is grilling for pre-set initial periods.

A scraping or sweeping bar (8) can be engaged as part of the movement of the product rack (2) ejection. As the ejection of the product rack (2) moves forward horizontally a scraper (8) will push any debris or spillage off the white (or whatever finish) background tray (10) and into a catch tray (15).

Operation

In order monitor the grilling or colouring process of foodstuff in the oven chamber, after a preferred initialisation procedure which will be described hereafter, the foodstuff positioned on the conveyance in the monitoring position in the field of view of the radiation receiver 16. The light 18 projects light onto the monitoring position and the foodstuff. The radiation receiver has a number of image pixels which receive emission or radiation emissions from the monitoring position and converts the image data into digital data for analysis. The data is preferably data representative of the colour but may also be simply recordings of the characteristics of the emissions. The data is then compared against known reference data for the foodstuff. The known reference data is pre-recorded data representing the foodstuff in the desired state of preparedness.

The comparison gives an indication of the progress that the foodstuff is to completion of cooking process. Once the comparison has been made, if the cooking progress is considered to be less than 100% complete, the conveyance and foodstuff is returned to the heating position for further heat treatment and cooking. As a safety margin, it may be desirable to return the foodstuff for further cooking only if it is less than 95% complete.

In a preferred embodiment, the processor may make an assessment of the level of completion of the foodstuff to completion of cooking. Based on the time since the commencement of the cooking or heat treatment process, the processor may be provided with algorithms to revise the duration time of cooking required and recalculate the estimated completion time. The foodstuff is then returned to the heat treatment position for further cooking or heat treatment for a new review time which is at or less than the estimated completion time.

Once the new review time has been reached, the foodstuff may then be moved to the monitoring position and the monitoring, comparison and preferably recalculating of completion time step repeated.

Once the foodstuff has reached a level of completion determined by the comparison with the known reference data of a completed foodstuff, the foodstuff is no longer returned to the heating position.

As an example of monitoring the grilling or colouring process, the invention uses the radiation receiver (16) such as a camera to take photographs at timed intervals during the process. The radiation receiver (16) is linked to the data processor (17) such as computer to analyse the number of image pixels of a particular colour or colours in a given area. By reading image pixel colours such as black, brown, orange, yellow and white, in different or the same number per given area and comparing it against known references, the colouring or cooking process can be halted when the colour count is reached. Figures 3 illustrate an example of how the colour change on the food can be seen in the coloured pixels.

Each food type can have a different count of colour pixels depending on the food type and the chef's preference. Foods that show little change in colour due to the fact that they are already dark in colour or require heat to crisp but not colour (such as corn chips for nachos), can still cook or grill to the required level as the camera (16) can read the colour of the product when it is loaded, and register the amount of colour change, which may be slight, to bring it to the desired level of cook.

At the completion, of the colouring, cooking or heat treatment process, the cooking may be halted by either or all of the following methods:

(a) by turning off the heat source and energizing a buzzer or light.

(b) by pushing, dropping or fast feeding the product out of the heat.

(c) by lowering the product or raising the heat source from the product to halt colouring. The radiation receiver (16) receives radiation emissions from the product after it has been moved out and under the receiver in a monitoring station position. This enable the radiation receiver and the monitoring to be subjected to an environment which is more conducive to monitoring and less hostile on the monitoring equipment and process. As the monitoring position is adjacent the cooking position and the foodstuff itself will likely have steam, smoke and spatter coming from it is is preferable that a cleaning

arrangement is provided.

The cleaning arrangement of the invention includes a motorised roll of radiation transmissive tape (19) which may be transparent and covers the opening in the outer wall of housing and protects the lens from oil spatters and other debris circulating from the chamber.

When the radiation receiver (16) is not in use, or during the pause time between data collection, a plain reference screen 20 of known radiation emissive or reflective properties which is preferably white or may be any colour, may slide into place across the opening to protect the receiver from heat and permit the receiver to read the reference screen. When in this position, the radiation receiver (16) is adapted to receive radiation emitted or reflected from the surface of the reference surface. As the reference surface is of known emissive or reflective value, the data received can be compared with the known data. If the processed received data is found to vary beyond pre-set tolerances, the tape or liner (19) is deemed dirty or no longer has transmitting radiation properties in comparison to the known reference and the cleaning arrangement initiates a cleaning procedure. The tape or liner (19) is then advanced on spools, to advance a clean section of tape in front of the opening.

Thus any large impurities such as fat spatter that are present on the tape, are seen when the radiation receiver receives radiation with the reference cover across the opening in the housing, using the a pixel counting program, and this causes the tape to advance to a clean portion in front of the lens of the receiver (16). When the tape has been fully unrolled, the end section of tape may be provided with solid black print on the tape which instructs the processor that the tape cassette (19) needs replacing.

The radiation receiver (16) may be provided in a separate removable unit. The unit may include a housing contain the radiation receiver and a sub-housing containing the opening tape, spools to roll on the tape and reference cover may be combined as a separate removable cassette (19) to enable replacement of the tape when no clean tape is left unspooled. As the reference cover will itself eventually become dirty and not conform to the known reference data, the tape cassette (19) is provided with the screen as part of the replacement package, so the screen and the tape is fitted in a single inserting process. Should the tape advance but the pattern of debris stay intact, the processor (17) will detect the variation from the reference data and send a message to the processor (17) that the reference screen requires cleaning. Cleaning pads on the cassette (19) clean the reference screen as it slide back and forth, and these pads and screen are replaced as part of the cassette swap out process.

As part of the programming of the apparatus, after a pre-determined number of cooking cycles, it may be desirable to initiate a pre-test by the radiation receiver (16) to self- diagnose the quality and clarity of signal. With a known reference of known image data in the monitoring position, image data is received by the radiation receiver (16) then sent to the processer (17). If image data is analysed to be unclear, as described above, protective tape (19) will move over the radiation receiver (16) enough to cover entire lens area of the radiation receiver (16) and then the scraper arm (8) is initiated to sweep white background tray (10). If signal is still corrupt or unclear a fault will be registered to the user for attention.

The issues of having a receiver and lens in a hot and fatty, smoky environment can be overcome by various design elements, including the following:

1 . air cooling of receiver body by ducted fresh air from a fan or air blower (14);

2. minimizing the exposure time that the camera is subjected to the heat and fumes;

3. insulation within the fully contained vision unit (12);

4. a baffle to direct hot air away from vision unit (1 1 );

5. a strip of metal that swings down to close top part of cooking chamber when product rack is under elements (9);

6. as part of the vision unit a cover that can swing or slide when data collection is not required (20);

7. the use of a lens cover in the form of a ribbon of clear temperature resistant material (19), that moves a fresh portion in front of the radiation receiver (16).

While the heating is described using electrical elements (for example Kelrod type) the heating can be performed by gas flame or a combination of gas and electric power. Initialising procedure

In one example where the image data is converted to colour pixels, the number of black, brown, orange, yellow and white pixels per standard area is used as an indication of the degree of browning or cooking is set. To set the desired amount of colour on a product, a sample is first grilled to the exact level of colour required, and data on the pixilation is captured by the radiation receiver (16), analysed and stored by the processor (17).

Where the colour is not even on the sample, the operator can select (preferably by touch screen) the ideal colour, then the minimum and maximum that the product can be. In the case of beef steak for example, a lot of brown and black pixels can be chosen, whereas cheese or sliced bread for toast would select little black pixilation. Where small areas of the product may have black speckling, the software program can accept this as normal providing the surrounding pixel areas are not showing the same. This offers a level of flexibility so that a current in raisin toast for example, does not interfere with the readings. When grilling for example a crayfish tail, the tail can often be burnt by the time the thick body area is cooked. A great variance in height of the product across its area relative to the heating element is a common factor in localized burning of the area closest to the element or flame.

The number of colours seen as pixels need not be restricted to the ones described herein, as ranges in browns, yellows; etc. can permit very accurate control of the finished product. Alternatively numerical values or some other distinguishing indicia can be assigned which allows the information received from the surface to be analysed by the processor (17).

The software will read the product when first loaded and a scan that shows existing dark or light pixels will look for changing of the pixilation as the grilling process continues. An area that fails to change or is already darker than the finished result will be disregarded.

As a further example shown in figure 3, three samples of the new intended foodstuff product are prepared. Sample [1 ] is the raw uncooked foodstuff product, sample [2] is the ideal colour at the level of cook that is required, sample [3] is a sample of the foodstuff at an excess colour that would be considered to be at the outer limit of colour tolerance that the chef or operator would wish to serve.

The operator/user will use the computer software (17) to specify a colour spectrum limit where the uncooked and over cooked samples; photos [4] and [6] in figure 3 appear in the field of view of the camera (16) as only partial or even not able to be seen at all. Essentially the program filters the data from the radiation receiver so that the uncooked and overcooked samples are at the threshold of the filtered data and appear as zero response regions. A blackening out of the sample in the image data will mean that the pixel count of the data is zero or as low as possible. Thus the image data of perfectly cooked foodstuff is processed as above this threshold level.

Sample [2] (photo 5 in figure 3) that appears clear in the photo which has good outline definition, and a high pixel count. The image data is thus above threshold level. This enables the radiation receiver (16), processor (17) and software to count pixels during cooking and stop the process when the ideal pixel count is reached. The processor sets the image data of photo 5 as representing a perfectly completed cooked product and assigning this as the reference for a perfect pixel count of 100%. During the cooking process, the recording of image data when the foodstuff and conveyance is in the monitoring position occurs as a counting of pixels of from 0 to 100 % and this is used during the cooking process as an indication of the progress of the cooking of the foodstuff during the cooking process. The speed at which the pixel count changes from say, 20% to 40% can be used to determine how often the product should exit for further photos, and in what time period. This enables the processor (17) to assess the progress of the cooking process and if necessary adjust the estimated completion time.

As a preferred refinement of the programming of the processor and the recording and processing procedure, for each foodstuff, a database of estimated cooking times can be established in the cooking chamber. There is also an established time that any recipe product can be positioned in the heating position at the maximum heat prior to the foodstuff beginning to show colour; eg the first one minute or a time determined for individual products. As an initial pre-programmed time before the first reading of the progress of the cooking process, the computer (17) can avoid withdrawing the product from heat in this pre-programmed period, but then commence taking image data and comparing the pixel count percent up to 100% or a pre-set percentage according to the operator/chef's preference.

In a further refinement, the colouring speed of each product or the rate at which each product reaches the perfect pixel count of each product in a menu can be a pre-set input so that the regularity of colour checking can be predetermined as the colouring process and checking process advances towards a pixel count of 100%. Grill heat intensity - it is a further embodiment of the invention to reduce heat coming from heating source, by reduction in flame size or power where electrical elements (3&4) are used.

A further enhancement is to fit larger than typically required heating sources above and below grill tray, so that a very high amount of heat can be input when grill first turned on or when product is loaded and can withstand higher grill temperatures for the first minute or so.

The invention may also be used on very fast griller toasters which have become popular in commercial kitchens, and these generally require a combination of microwave, infrared heat, impinged air and convection heat. An oven with a very large heat bank system can also be used, storing the heat in ceramics etc, and releasing the heat when required. These machines require a well sealing door to avoid microwave leakage and wastage of heat. The use of the monitoring system as shown in Figure 2 can be used by incorporating an automatically opening door, and a mechanical system that is employed to open the door can be used to push the grill tray (or ceramic tile floor) out of the baking chamber, allowing the door to close and retain heat in the oven.

As the grilling process may be very fast, the use of the invention may be used to obtain the 'perfect' result every time. This is in comparison to the process used presently requiring a calculation of heat and time regulation on all products. The accurate control of colour will be the key success indicator to the process. Software in the processor (17) will control the timing or the receiver as to when the data is captured, when the data is captured and the basis for comparison of the data with the known data.

A further embodiment of the invention includes the use of the processor (17) to hold a library of recipe lists of products baked, with a record on file of the product, the colour scan pixel level, and other baking data such as temperature in the grill bay, element heat, cooking time, height setting on rack, time delayed before 1 ^st data collection etc.

A one touch recipe selection can be used to set the baking recipe and the finished colour preference.

Should any product come out lighter or darker than preferred, a selection button can show the reduced and increased colour preference available.

Figure 4 is a flow chart of a cooking process according to an embodiment of the invention. Initially a photo is taken of the background tray in the monitoring position. The image data is checked to ensure that there isn't any dirt or debris on the tray and that the light is sufficient. The product is then loaded onto the product conveyance in the monitoring position and the processor is set for the particular type of food. In the case of figure 4 the product is a slice of fruit loaf. Image data is collected from the product and recorded. The current state of the starting material can be measured against known references of uncooked, perfectly cooked and overcooked but acceptable for that product type. The known references can be periodically updated or can be established at the beginning of the day. The cooking cycle is commenced. For each cooking cycle there will be

predetermined estimated completion time and a time for the first monitoring step for that product type. The cooking process continues until the first monitoring time elapses. In the case of fruit loaf, that first monitoring time is 2 minutes. The foodstuff is removed from the heating position and moved to the monitoring position where image data is collected and compared to the reference data of the foodstuff completely (perfectly) cooked. Typically at this stage, the fruit loaf after 2 minutes of a 3 minute cooking cycle has a pixel count of 10%. The collected image data is compared against previously recorded image data or based on past experience. The previously collected data establishes an anticipated pixel count and is the count that would normally be expected if the initially predicted completion time were to apply. The processor has an algorithm which adjusts the completion time based on the difference between the current image data and anticipated image data. This would be done based on the image data converted to pixel counts. The foodstuff is returned to the heating position for a period of time when the cooking of the foodstuff will be at a higher percentage of completion, say 40%. and Steps 5 and 6 are repeated one or more times and the rate of change of colour change of the foodstuff is monitored and the completion time varied accordingly. 8. After one or more passes from the heating position to the monitoring position, the cooking of the image data for the foodstuff recorded in the monitoring position foodstuff will reach 95-100% of a perfectly cooked foodstuff. This corresponds to a pixel count of 100%. At this point, the foodstuff is not returned to the heating position and an alarm sounds alerting the cook or attendant.

Claims

1 . A method of monitoring cooking of a foodstuff in an apparatus, the cooking apparatus comprising at least one heating element for applying a heat treatment to a cooking position, at least one food conveyance upon which the foodstuff is positioned and a data receiver having a field of vision covering an inspection position comprising the steps of ;

(i) loading a foodstuff onto the at least one food conveyance and selecting a preprogrammed cooking cycle

(j) recording data of the foodstuff on the food conveyance when the food

conveyance is initially in the inspection position;

(k) moving the food conveyance into the cooking position to start the cooking time and subjecting the foodstuff to heat treatment for a period of time according to a pre-programmed cooking cycle;

(I) moving the food conveyance into the inspection position after the initial period of time specified by the pre-programmed cooking cycle and recording image data of the foodstuff;

(m)comparing the image data with known image data indicative of a pre-set cooked condition;

(n) determining an adjusted cooking time to reach the pre-set condition based on at least the current image data and elapsed cooking time since the start of cooking

(o) moving the food conveyance into the cooking position and subjecting the

foodstuff to heat treatment for the adjusted cooking time; and

(p) causing the foodstuff to be removed from the heat treatment after adjusted

cooking time.

2. The method of claim 1 wherein steps (a) - (d) are repeated until the recorded image data is within acceptable tolerance of the known image data indicating the preset condition.

3. The method of claim 1 wherein the adjusted cooking time is further adjusted by

(a) moving the food conveyance into the inspection position after the adjusted

cooking time and recording image data of the foodstuff; (b) comparing the image data with known image data indicative of a reset cooked condition;

(c) determining a further adjusted cooking time to reach the pre-set cooked

condition; and

(d) moving the food conveyance into the cooking position and subjecting the

foodstuff to heat treatment for the further adjusted cooking time.

4. The method of claim 1 or 2 further comprising an initial step of

(a) prior to loading the foodstuff onto the foodstuff conveyance, collecting image data of a reference background in the inspection position;

(b) comparing the collected image data of the reference surface against known

stored data of the reference surface;

(c) initiating a cleaning procedure of the transmission window or the reference

surface or transmission window and reference surface if the image data recorded from the reference surface varies from the known data.

5. The method of claim 4, wherein a reference surface of known emissive or reflective values, is in or movable to within at least the field of view of the receiver to enable comparative emissive or reflective data to be collected from the reference surface and compared with stored reference data as an indication of whether the reference surface or transmission surface requires cleaning.

6. The method of claim 5 wherein a cleaning arrangement to clean the

transmission window of the receiver or reference surface is activated to clean the transmission window of the receiver or reference surface.

7. A system for monitoring the changes in the surface of a foodstuff in a heated cooking apparatus, the cooking apparatus comprising a cooking position and an inspection position, at least one heating element for applying a heat treatment to the cooking position, at least one food conveyance upon which the foodstuff is positioned and moved between the cooking position and inspection position, he system

comprising:

a) and a data receiver having a field of view covering the inspection position being adapted to receive data of the radiation emitted or reflected from the surface of the foodstuff in the inspection position; b) a processor communicating with the data receiver for receiving radiation data and determining whether the recorded data is indicative of the foodstuff reaching a pre-set condition, c) an actuator to move the foodstuff conveyance between the cooking position and inspection position so that the foodstuff can be inspected; and d) an alarm to indicate that the foodstuff has reached a pre-set condition.

8. The system of claim 7 wherein the processor compares the data from the data receiver when the foodstuff is in the inspection position to stored data indicative of a pre-set cooking condition;

9. The system of claim 8 further comprising a reference surface of known emissive or reflective values, in or movable to within at least the field of view of the data receiver when the foodstuff is not in the inspection position, the data receiver receiving data to enable comparative emissive or reflective data to be collected and compared with stored reference data.

10. The system of claim 9 further comprising a cleaning arrangement to clean the transmission window of the receiver, the cleaning arrangement being activatable when the comparison of data received from the reference surface indicates a difference outside of tolerance limits from known stored data of the reference surface.

1 1 . The system of claim 7 wherein an air blower is provided to minimise the amount of material contacting and potentially affecting the transmissibility of the window.

12. The system of claim 10 wherein the transmission window further comprises a disposable surface liner having a replacement mechanism which replaces the surface liner when the data of emissions or reflective radiation from the known reference surface differs outside of tolerance limits from the known data of the reference surface.

13. The system of claim 12 wherein the disposable surface includes a continuous strip, the continuous strip being displaceable at least the dimensions of the window to replace the entire surface covering the transmission window.

14. A method of cooking foodstuff in a heated cooking apparatus, the cooking apparatus comprising at least one heating element for applying a heat treatment to a cooking position, at least one food conveyance upon which the foodstuff is positioned and a data receiver having a field of vision covering an inspection position, the method comprising the steps of:

a) moving the foodstuff on the food conveyance into an inspection position in the field of view of the data receiver; b) recording data of the radiation emissions or reflections from a surface of the foodstuff; c) determining whether the recorded data is indicative of the foodstuff reaching a pre-set condition; and either i) moving the foodstuff into the cooking position for further heat treatment if the condition has not been met; or ii) indicating that the foodstuff has reached a pre-set condition.

15. The method of claim 14 wherein the step of determining whether the recorded data is indicative of the foodstuff has reached a pre-set condition comprises the steps of comparing the recorded data of the radiation emissions or reflections with a stored set of data indicative of a pre-set cooking condition.

16. The method of claim 15 wherein the field of view of the receiver is divided into a number of segments which individually are compared against the data indicative of a pre-set condition.

17. The method of claim 16 wherein the data from a segment or the full field of view is analysed and averaged over the field of view to provide averaged data and a comparison is made between the averaged data and the data indicative of a pre-set condition, the averaged data being the same as the data of the pre-set condition being indicative of the condition being met.

18. The method of anyone of the preceding claims 14 - 17 wherein the indication that the recorded data in at least part of the field of view is the same as the data indicative of the pre-set condition is an indication that the condition has been met.

19. An apparatus for cooking foodstuff comprising g) at least one food conveyance upon which foodstuff is positioned; the at least one conveyance being movable between an inspection position and a cooking position; h) at least one heating element over the cooking position of the at least one foodstuff conveyance; i) a data receiver having a transmission window and a field of view including at least the foodstuff on the conveyance in the inspection position, the receiver being adapted for receiving image data of radiation or reflective emissions from the foodstuff surface; j) a processor communicating with the receiver for receiving image data and

comparing the data to stored data indicative of a pre-set cooking condition; k) a reference surface of known emissive or reflective values, in or movable to

within at least the field of view of the receiver to enable comparative emissive or reflective data to be collected from the reference surface and compared with stored reference data as an indication of whether the reference surface or transmission surface requires cleaning

I) a cleaning arrangement to clean the transmission window or reference surface.

20. A method of cooking foodstuff in a heated cooking apparatus the cooking apparatus comprising at least one heating element for applying a heat treatment to a cooking position, at least one food conveyance upon which the foodstuff is positioned and a data receiver having a field of vision covering an inspection position, the method comprising the steps of:

21 . The method of claim 21 wherein the transmission window further comprises a disposable surface liner, the cleaning procedure comprises replacing the surface liner when the data of emissions or reflective radiation from the known reference surface differs outside of tolerance limits from the known data of the reference surface.

22. The method of claim 21 wherein the disposable surface liner includes a continuous strip, the replacement of the surface liner comprising displacing the surface liner at least the dimensions of the window to replace the entire surface of covering the transmission window.