Method and apparatus for monitoring the status and transfer of food products

This application is a division of co-pending U.S. application Ser. No. 09/692,578 filed on Oct. 19, 2000, and entitled, “Method and Apparatus for Monitoring the Status and Transfer of Food Products”, and further claims the benefit of U.S. Provisional Application No. 60/160,878, filed on Oct. 22, 1999, and entitled “Method and Apparatus for Monitoring the Status and Transfer of Food Products”, the disclosures of which are incorporated herein by reference.

This invention relates generally to systems which monitor a status of a product, such as prepared food, and more specifically relates to automated product status systems which communicate the status of multiple food products to food preparers, and enable the transfer of food products within the system.

The control of product freshness and quality has always been a major concern with industries, such as restaurants, dealing with the sale of perishable goods, such as prepared foods. Numerous inventory control systems exist which track parameters such as the origin, quantity used, quantity stored and the age of products. However, an automated system, which monitors the shelf life of perishable goods, has not yet been placed into practice. In addition, many of the systems and methods for monitoring product status currently in use cannot ensure that the oldest product is used first or that available product is optimally used to minimize waste. Therefore, it would be advantageous if such a system or method could accurately and efficiently track the status of perishable goods while providing a means for reducing the amount of waste.

In the restaurant industry, at least two durations of time become important variables to monitor. One is a hold time, which is the shelf life of prepared food or the duration of time during which a particular product meets a set of standards imposed by the food provider. The second variable is a cook time, which is the duration of time required to cook and/or prepare additional product. The cook time must be accounted for if product is to be continually available. In conventional product status systems, employees or workers engaged in the preparation of food typically monitor the hold and cook times, and are required to set, monitor and reset a different timer for each of the large number of food products being sold. Such a situation results in a tremendous inefficiency in the use of manpower and a reduction in productivity. In addition, the potential for human error can lead to an unacceptable or dangerous product being sold to the consumer. Therefore, it would be advantageous if the hold time, cook time and other variables relevant to the preparation and sale of the food product could be automatically monitored and provided to the worker in summary format without undue human intervention.

In most restaurants, the status of products and the need for additional products is communicated by shouting requests or commands across the kitchen or other food preparation area. This results in additional noise, confusion and often misinformation, which ultimately affects the quality of the food being provided to the consumer as well as the environment, provided for the consumers enjoyment within the restaurant. Therefore, a system and method that could effectively communicate the status of each of many products being offered for sale to all workers without the need for individual communication between workers would be advantageous.

Conventional methods of tracking product status do not provide an efficient means for collecting and processing information concerning loss or waste of perishable goods once they have been prepared for sale; the rate of sale for each product during different periods of the day and promotional events; and worker productivity. Therefore, it would be advantageous if a product status system could provide information on such variables for use in management databases and as a planning tool.

Many of the product status systems in the prior art, such as those using individual timers monitored by workers for each of a number of different products being sold, require that additional timers be used, and that the workers become familiar with additional hold and cook times when new and/or different products are sold. Therefore, it would be advantageous if a product status system was flexible and readily upgradeable to adapt to different types and quantities of food products without burdening the workers and decreasing productivity.

It is an object of the present invention to provide a product status system and a method for indicating the stock status of food products, which communicate the status of food products to all workers rather than requiring individual communication between workers.

It is another object of the present invention to provide a product status system and a method for indicating the stock status of food products, which monitor shelf life and displays stock status corresponding to a pan of food product in digital format to reduce errors.

It is yet another object of the present invention to provide a product status system and a method for monitoring the status of food products, which enable complete or partial transfers of a food product throughout the system to ensure availability of the food product according to demand from different locations in the system.

It is a further object of the present invention to provide a product status system and a method for monitoring the status of food products, which do not permit cross transfers between pans of food products located in non-corresponding locations unless specifically programmed to do so.

It is an object of the present invention to provide a product status system and a method for monitoring the status of food products, which enable station worker interface boards to be substantially identical regardless of whether they are mounted on the front or rear of the station.

It is another object of the present invention to provide a product status system and a method for programming and displaying the amount of food products to be prepared that can be manually adjusted or automated according to the time, the day, promotional events, the anticipated rate of sale, and the like.

It is yet another object of the present invention to provide a product status system and a method for monitoring the status of food products that facilitates the use of the oldest food product first, thereby decreasing the waste of perishable goods.

It is a further object of the present invention to provide a product status system, which is flexible and readily upgradeable and/or programmable to meet the requirements imposed by different types and quantities of food products offered for sale.

It is an object of the present invention to provide a product status system and a method for monitoring the status of food products, which eliminate the need for workers to monitor individual variables for a variety of food products being sold, such as a shelf life, a stock status and a quantity of food product to cook, which improves overall operational efficiency, decreases waste associated with a perishable food product, decreases the manpower required to prepare the food product for sale and increases the efficiency of individual workers.

In accordance with the present invention, a product status system is provided which monitors the status and storage location of a prepared food product including a processing circuit, a food product status switch, a food product status indicator, and a storage timer. The food product status indicator displays the status of the food product in a particular storage location. The storage timer counts the duration of time the food product has been stored at the storage location. The status indicates whether or not the prepared food product is available in the storage location, whether the storage time of the food product has exceeded an acceptable food product hold time, and when additional food product should be cooked in order to be ready before the storage time of existing food product exceeds the hold time.

The product status system can include a plurality of storage locations, such as a source storage location and a destination storage location, between which the food product is transferred along with the storage time associated therewith. In this case, the storage time from the source storage location is transferred to a destination storage timer associated with the destination storage location, and the destination storage timer counts the duration of time the food product has been stored at both the source and destination storage locations. The status can also indicate which of two or more source storage locations contains the food product, which has been stored for the greatest length of time to facilitate use of the oldest product first. In addition, the status can indicate which of two or more destination storage locations to transfer a given food product into.

The product status system can include a display which displays the status, a pan fill level, an activity level and a day part associated with the prepared food product. Each of the food products can have a different pan fill level associated therewith, which represents a quantity of food product to prepare when the associated storage location becomes empty. The activity level represents an overall rate of sale for all of the food products in a restaurant, and can affect the pan fill level for any or all of the food products.

In further accordance with the present invention, a method for monitoring the status and storage location of a prepared food product is provided, which includes the steps of supplying the prepared food product to the storage location, changing the state of the food product status indicator, initiating a storage timer to count the storage time for the food product in the storage location, comparing the storage time with the acceptable food product hold time, changing the state of the food product status indicator if the storage time exceeds the hold time and changing the state of the food product status indicator when the storage location no longer contains the food product.

The storage time can be transferred with the food product if there are two or more storage locations, such as the source storage location and the destination storage location. In this case, the state of the food product status indicator is changed to indicate when the duration of time the food product has been stored at both the source and destination storage location exceeds the hold time. The state of the food product status indicator can also be changed to indicate which of two or more storage locations contains food product which has been stored longer, and which of two or more storage locations a given food product undergoing a transfer can be transferred into.

These and other objects, features, and advantages of the present invention will be apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings.

FIG. 1 is a block diagram of a product status and transfer system formed in accordance with the present invention and applied to a restaurant.

FIG. 2 is a front view of a workstation, such as a drive-through station, a front counter station, or a holding station of the product status and transfer system formed in accordance with the present invention.

FIG. 3 is a front view of a display and the holding station of the product status and transfer system formed in accordance with the present invention.

FIG. 4 is an enlarged view of the display shown in FIG. 3 .

FIG. 5A shows a product label, product status switches, and product status indicators, which are located on the stations formed in accordance with the present invention.

FIG. 5B shows an active switch, an active indicator, a transfer switch, and a transfer indicator, which are located on the stations formed in accordance with the present invention.

FIG. 6 is a flowchart of an active/inactive station routine used in a method formed in accordance with the present invention.

FIGS. 7A & 7B are flowcharts of a product transfer routine used in the method formed in accordance with the present invention.

FIG. 8A is a flowchart summarizing the product transfer routine shown in FIGS. 7A and 7B .

FIG. 8B is a block diagram showing the operation of a multiple transfer used in the method formed in accordance with the present invention.

FIG. 8C is a flowchart of a minimum stock level routine formed in accordance with the present invention.

FIGS. 8D and 8E show a front and rear view of the holding station, respectively.

FIG. 8F shows a flowchart for a product transfer algorithm formed in accordance with the present invention.

FIGS. 9A and 9B are flowcharts of the method for monitoring a status for each of a plurality of products formed in accordance with the present invention.

FIG. 10 is a circuit board level block diagram of the product status and transfer system formed in accordance with the present invention.

FIG. 11 is a schematic diagram of a station/worker interface board (SWIB) of the product status and transfer system formed in accordance with the present invention.

FIG. 12 is a schematic diagram of an active/transfer board (ATB) of the product status and transfer system formed in accordance with the present invention.

FIG. 13 is a schematic diagram of a station interface board (SIB) of the product status and transfer system formed in accordance with the present invention.

FIGS. 14A-14J are schematic diagrams of a station control board (SCB) of the product status and transfer system formed in accordance with the present invention.

FIGS. 15A-15L are schematic diagrams of a display board (CDB) of the product status and transfer system formed in accordance with the present invention.

Top Level Description of Product Status and Transfer System

FIG. 1 shows a top-level block diagram of a product status and transfer system 10 formed in accordance with the present invention and applied to a restaurant serving prepared food. The product status and transfer system (PSTS) 10 preferably includes one or more front counter stations 12 , one or more drive-through stations 14 , a holding station 16 , and a display 18 . The display 18 may be centrally located. The front counter station 12 is preferably located near a serving counter and a corresponding cash register 20 . The drive-through station 14 is preferably located near a window 22 through which workers service drive-up customers in their cars 24 . The holding station 16 and the display 18 are preferably located in a centralized location, which is readily accessible to the front counter stations 12 and the drive-through station 14 . Seating 26 may also be provided within the restaurant.

The drive-through station 14 and the front counter stations 12 preferably each enable two sandwich makers 28 standing on opposing sides of the stations 12 , 14 to remove cooked product from the stations 12 , 14 and to prepare the cooked product for sale to a consumer. The holding station 16 preferably enables at least one expeditor 30 to cook the food product and place the cooked product into the holding station 16 . A store manager 32 is preferably responsible for managing the operation of the restaurant. The sandwich makers 28 and the expeditor 30 are collectively referred to as workers 28 or workers 30 according to the station they are working at.

FIG. 2 shows a pictorial representation of a front view of the front counter station 12 , drive-through station 14 and holding station 16 , which are collectively referred to as the station 12 , 14 , 16 . The station 12 , 14 , 16 preferably includes at least one active switch 34 , at least one active indicator 36 , at least one transfer switch 38 , at least one transfer indicator 40 , product status switches 42 , product status indicators 44 and product labels 46 . The holding station 16 is substantially the same as the front counter station 12 and the drive-through station 14 , except that the holding station 16 is preferably designed for use by one worker 30 . Thus, since the product located in the holding station 30 is intended to be accessed by only one worker 30 , preferably only one active switch 34 , one active indicator 36 , one transfer switch 38 and one transfer indicator 40 exist on the holding station 16 . In contrast, two of each of these switches and indicators exist on each of the front counter station 12 and the drive-through stations 14 .

The stations 12 , 14 , 16 can preferably each accommodate up to 24 different pans 48 of food product as shown in FIG. 2 . Each product status switch 42 and product status indicator 44 corresponds to a particular pan 48 of product. The stations 12 , 14 , 16 preferably include three rows 50 of product status switches 42 , product status indicators 44 and product labels 46 . Each row 50 corresponds to an upper row of pans 52 and a lower row of pans 54 . The upper row of pans 52 is preferably used by the worker 28 on one side of the station 12 , 14 , while the lower row of pans 54 is preferably used by the worker 28 on the opposing side of the station 12 , 14 . Thus, the upper row of pans 52 holds what is preferably considered to be primary pans by the worker on one side of the station 12 , 14 , while the lower row of pans 54 holds what is preferably considered to be secondary pans by the worker 28 on the opposing side of the station 12 , 14 . Conversely, the lower row of pans 54 holds what is considered to be primary pans by the worker 28 on one side of the station 12 , 14 , while the upper row of pans 52 holds what is considered to be secondary pans by the worker 28 on the opposing side of the station 12 , 14 . The primary pan corresponding to a particular side of the station 12 , 14 is preferably used exclusively by the worker 28 located on that side of the station 12 , 14 . However, should the primary pan be empty, the worker 28 can use the product located in what is considered to be the secondary pan (which is considered the primary pan for the worker 28 on the opposing side of the station 12 , 14 ).

The use of upper and lower rows of pans 52 , 54 effectively enables two workers 28 to work at the station 12 , 14 simultaneously without interfering with each other. Since as already described, there is preferably only one worker 30 at the holding station 16 , that worker 30 preferably has equal access to both upper and lower rows of pans 52 , 54 . The food products are preferably located within pans 48 at the stations 12 , 14 , 16 which are ergonomically advantageous according to a rate of sale for that product. In other words, those products that are sold most often are preferably placed in the location most easily accessed by the worker at the station 12 , 14 , 16 . Also, the same product is preferably placed in substantially the same location in each of the stations 12 , 14 , 16 . The product label 46 preferably indicates the identity of the food product or the selectable menu, which is located in the pan 48 immediately above and immediately below the product label 46 . It is important to note that the product label 46 , the food product status switch 42 , and the food product status indicator 44 are preferably located in alignment with the corresponding food product pan 48 . Alternatively, the identity of the food product or selectable menu associated with the pan 48 may be electronically displayed and changed in response to a selectable menu switch. The products immediately above and below the product label 46 are preferably the same since this allows two workers 28 to access the same product at the same station simultaneously, as well as the concept of primary and secondary pans described above.

The product status indicators 44 are preferably shaped in the form of an arrow. The product status switch 42 and the product status indicator 44 modify and indicate, respectively, the status of the products located in the pan pointed to by the corresponding product status indicator 44 . For instance, as shown in FIG. 2 , the product label 46 , the product status indicator 44 A and the product status switch 42 A correspond to an upper pan 48 A. Likewise, the product label 46 , the product status indicator 44 B and the product status switch 42 B correspond to a lower pan 48 B. If the products in corresponding upper and lower pans are different, the product label 46 can be divided into an upper portion indicating the identity of the product in the upper pan 48 A, and a lower portion indicating the identity of the product in the lower pan 48 B.

The active switch 34 and the active indicator 36 can modify and display the activity of the station 12 , 14 , 16 . The transfer switch 38 and the transfer indicator 40 are used to initiate and indicate a transfer of the food product between locations in the same or different stations 12 , 14 , 16 .

FIG. 3 shows the holding station 16 , which is equivalent to the drive-through station 14 and the front counter station 12 , except that one worker 30 preferably operates the holding station 16 , and both the upper and lower rows of product pans 52 , 54 are accessed by that worker 30 . In addition, the display 18 is preferably located in a position which is viewable by the worker 30 operating the holding station 16 , such as above the holding station 16 as shown in FIG. 3 .

Top Level Summary of Operation

At the beginning of a day in the restaurant, the worker 30 situated in front of the holding station 16 cooks a predetermined quantity or pan fill level of each product as indicated on the display 18 , and stores the cooked product in the appropriate pan 48 in the holding station 16 . Each product has a corresponding hold time, which represents a shelf life of the cooked product or a duration of time during which the product has an acceptable quality and can be served to consumers. The worker 30 then presses the product status switch 42 on the holding station 16 corresponding to the pan 48 just filled indicating the presence of cooked product, and triggering a timer corresponding to the location just filled to initiate a count of the storage time for the corresponding food product. The cooked product is then transferred from the holding station 16 to the front station 12 and the drive-through station 14 along with the storage time corresponding to the product being transferred.

As product is prepared and sold to consumers, the cooked food products at the stations 12 , 14 are depleted. When the last unit of a particular product has been removed from one of the stations 12 , 14 , the worker 28 presses the product status switch 42 corresponding to the depleted product, which indicates that there is an absence of the depleted product in a particular location in the station 12 , 14 via a corresponding product status indicator 44 on the display 18 . The worker 30 at the holding station 16 observes the product status indicator 44 corresponding to the depleted product, and either cooks fresh product or transfers existing cooked product from the holding station 16 to the station 12 , 14 requiring the cooked product.

If one of the cooked food products is retained in one of the stations 12 , 14 , 16 for a time which exceeds the hold time for that particular product, the corresponding product status indicator 44 will indicate that the product should be discarded rather than being sold to the consumer. The product status indicator 44 will also warn the workers 28 , 30 that the hold time is about to expire by turning yellow to indicate that additional product must be cooked in order to have cooked product before the existing product expires. A cook time represents a duration of time required to cook the corresponding product. The product status indicator 44 preferably turns yellow when the storage time for the product equals the hold time minus the cook time. Thus, enough time is provided to cook additional product prior to the expiration of existing cooked product. The product status indicators turn green to indicate that unexpired food product is available at a particular location in a station 12 , 14 , 16 , and turn red to indicate the absence of the food product at a particular location in the station 12 , 14 , 16 .

Active/Inactive Station

As already described, each of the stations 12 , 14 , 16 includes at least one active switch 34 and at least one active indicator 36 . Additional active switches and indicators may be included to indicate activity of the upper and lower pans of the station 12 , 14 , as shown in FIG. 5B . The front counter station 12 and the drive-through station 14 each have two active switches 34 and two active indicators 36 . One active switch 34 and one active indicator 36 , as shown in FIG. 5B , correspond to each side of the station 12 , 14 . Initially upon power-up, all stations 12 , 14 , 16 are placed in an active mode in which each of the active indicators 36 is illuminated. Thereafter, the workers 28 , 30 may select any of the active switches 34 which function to place the station 16 or side of the station 12 , 14 corresponding to the active switch 34 in an inactive mode. The active indicator 36 is not illuminated in the inactive mode.

When the station 12 , 14 , 16 is in the active mode, each of the product status indicators 44 are illuminated and indicate the status of the corresponding product. When the station 12 , 14 , 16 is in the inactive mode, each of the product status indicators 44 on the corresponding station 16 or side of the station 12 , 14 , as well as the product status indicator 44 corresponding to the inactive station 12 , 14 , 16 located on the display 18 are turned off. Activating any one of the active switches 34 causes the corresponding station 16 or side of the station 12 , 14 to toggle between the active mode and the inactive mode.

FIG. 6 is a flowchart showing the operation of the stations 12 , 14 , 16 during an active/inactive station routine. The station idles in step 56 until the active switch is depressed or selected, and then determines whether the station is currently in the active mode in step 58 . If the station is not in the active mode, the station enters the active mode in step 60 wherein the active indicator on the inactive station is illuminated and the product status indicators on the active station indicate the status of the corresponding products. However, if the station is in the active mode in step 58 , the station enters the inactive mode in step 62 wherein the corresponding active indicator and the product status indicators on the inactive station are turned off. However, timing for any products being timed prior to entry into the inactive mode continues during the inactive mode. Following steps 60 and 62 , the routine again idles in step 56 waiting for the next selection of the active switch. It is to be noted that the product status indicators on the display reflect the same status as the corresponding product status indicators on the stations. Therefore, if the station is in the inactive mode, the product status indicators on the display corresponding to the inactive station are off.

Product Timers

The product status and transfer system 10 includes at least one timer for each of the preferably 12 different products in the preferably 24 different product locations in each of the stations 12 , 14 , 16 . When fresh product is placed in a particular pan 48 in the station 12 , 14 , 16 , the corresponding product status switch 42 is selected by the worker 28 , 30 until the corresponding product status indicator 44 turns green, which triggers the timer to begin counting the storage time. The green product status indicator 44 indicates that the pan 48 contains unexpired product. Preferably, the storage time is counted by loading the hold time into the timer when fresh product is first placed into a particular pan 48 , and continuing to count down the hold time until the corresponding food product has been depleted, or the timer reaches zero indicating that the storage time has reached the hold time.

The cook time corresponding to any given product is that duration of time necessary to cook the particular product. If the value remaining on the timer is less than or equal to the cook time, then the corresponding product status indicators 44 turn yellow indicating to the worker 30 at the holding station 16 that additional product should be cooked since the product corresponding to the yellow light is about to expire. When the timer has counted down to zero, the corresponding product status indicator 44 flashes slow red indicating that the product remaining in the corresponding pan has expired and should be discarded rather than being served to the consumer.

Product Status

As already described above, each of the 24 locations in each of the stations 12 , 14 , 16 has a corresponding product label 46 , product status switch 42 and product status indicator 44 as shown in FIGS. 2, 3 and 5A . Each of the product status indicators 44 on each of the stations 12 , 14 , 16 has a corresponding product status indicator 44 on the display 18 , which displays substantially the same status displayed to the workers 28 , 30 at the stations 12 , 14 , 16 . Table 1 provides a summary of the status and action to be taken for each of the colors and flashing speeds provided by the product status indicators 44 .

Product Transfer

Each of the stations 12 , 14 , 16 preferably includes at least one transfer switch 38 and transfer indicator 40 , as shown in FIGS. 2, 3 and 5B . The front counter station 12 and drive-through station 14 both have two transfer switches 38 and two transfer indicators 40 . One transfer switch 38 and one transfer indicator 40 correspond to each side of the station 12 , 14 . The holding station 16 has one transfer switch 38 and one transfer indicator 40 since preferably only one side is accessed.

FIGS. 7A and 7B are flowcharts of the operation of a product transfer routine. The station idles in step 64 until the transfer switch is selected. Once the transfer switch is selected, the routine continues to step 66 in which the transfer indicator on the corresponding station or side of the station, which is now considered to be a source station or location, is illuminated. The source station enters a transfer mode in step 68 , and the routine performs a background process in step 70 , which determines whether a predetermined transfer time has expired. If the transfer time has expired, the system exits the transfer mode in step 71 , and the routine proceeds back to step 64 . If the transfer time has not expired, the background process in step 70 continues to idle.

After pressing the transfer switch on the source station, the product status indicator corresponding to the product which has been stored the longest flashes fast green, which indicates to the worker which product is the oldest and facilitates the use of the oldest product first. The product status indicators corresponding to locations holding products having a transfer in progress flash fast red indicating that the hold time may be transferred into these locations in step 74 . The worker removes the product to be transferred from a source location in the source station, which is preferably the product corresponding to the product status indicator which is flashing fast green, and presses the corresponding product status switch which makes the corresponding storage time available to be transferred out in step 76 . The worker then places the product being transferred into a destination location in a destination station in step 78 . The destination station can be the same station as the source station. The destination location can also be the same location in the same station as the source location. The products are preferably transferred while in the pans 48 . However, a portion of the food product in the pan may be transferred to more than one destination location. The destination location may be the same as the source location.

The flowchart continues on FIG. 7B in which the worker presses the transfer switch on the destination station and fills the destination location with the product being transferred in step 80 . The empty pans in the destination station corresponding to product with a transfer in progress will flash fast red indicating an empty pan with a potential for accepting the product being transferred. The worker presses the product status switch in step 82 corresponding to the destination location filled in step 78 , and the corresponding product status indicator turns green in step 84 indicating that the hold time, which was transferred out of the source station, has now been transferred into the destination location along with the product that was transferred. If only a portion of the product transferred out of the source location was transferred into the destination during a so-called “multiple transfer”, the remaining product can be transferred to additional destination locations including back to the source location in step 85 . If additional transfers are desired, the routine returns to repeat steps 78 , 80 , 82 and 84 until no additional transfers are desired and the routine returns. This completes the product transfer routine until the transfer switch is again selected.

The product transfer routine is essentially a very straightforward and simple process, which can readily be performed by workers having almost any level of skill. FIG. 8A shows a summarized form of the product transfer routine taken from the viewpoint of the worker. If the worker wishes to transfer product from one location to another, the worker selects or presses the transfer switch corresponding to the source station in step 86 and removes the product to be transferred in step 88 . The worker then presses the product status switch corresponding to the source location in step 90 . The worker transfers the product to the destination location and selects the transfer switch corresponding to the destination location in step 92 . The worker selects the product status switch corresponding to the destination location in step 96 . If some of the product transferred from the source location has not been transferred to the destination location, additional transfers can be made in step 97 via the reiteration of steps 92 , 94 and 96 until additional transfers are no longer desired, at which point the routine returns. It is to be understood that the product transfer routine transfers not only product from one station to another, but also transfers the elapsed storage time corresponding to the product being transferred. This ensures the accurate maintenance of the storage time for each product regardless of the transfer of products within the system.

FIG. 8F is a flowchart of an algorithm that enables the product status system to perform the product status transfer routine shown in FIG. 7A . The holding station queries the stations in step 65 to determine if the corresponding transfer switch has been selected at any of the stations. If the transfer switch has been selected in step 67 , the holding stations obtains an array of storage times from the station corresponding to the transfer switch selected in step 69 . The array includes twelve numbers representing the storage times for each of the twelve products stored in either the upper or lower pans in any of the stations. If the transfer switch has not been selected at any of the stations, the algorithm returns to re-execute step 65 from step 67 .

The array of storage times is stored in a buffer within each of the stations in step 71 . If the transfer switch has been selected at the same or another station in step 73 , that station will transfer the array of storage times from its buffer to its storage timers in step 75 . If the transfer switch has not been selected in step 73 or after the array of storage times is transferred to the storage timers, the algorithm determines whether the predetermined transfer time has expired in step 77 . If the transfer time has expired, the algorithm returns to step 65 . If the transfer time has not expired, the algorithm returns to re-execute step 73 .

FIG. 8B is a block diagram showing the multiple transfer of food product between the source location and one or more destination locations. The food product and the elapsed storage time corresponding to the food product are transferred from the source location to the destination location in response to activation of the transfer switch corresponding to the source station and the product status switch corresponding to the source location as well as activation of the transfer switch corresponding to each of the destination stations and the product status switch corresponding to each of the destination locations. The source location can also be one of the destination locations by activating the transfer switch corresponding to the source station and the product status switch corresponding to the source station as indicated by arrow 79 . In this way, the multiple transfer of product can be made from the source location back to the source location and one or more destination locations.

As an alternative to selecting the transfer switch 38 , the transfer of food product may be initiated by pressing and holding the product status switch 36 . This results in a significant reduction in the quantity of electromechanical components required by the system, which increases reliability and reduces manufacturing costs.

Minimum Stock Levels

FIG. 8C shows a flowchart of a minimum stock level routine, which is designed to inactivate or close storage locations when there are more storage locations are open than are required to hold a given stock level of the prepared food product. The stock level is equal to the total number of open stations for a given prepared food product multiplied by the pan fill level for that product. For instance, if the total number of stations open for burgers is 5 and the pan fill level for burgers is 8, the stock fill level is 40. However, the stock level indicates a preferred quantity of units of a given prepared food product, which should be present in the restaurant at any given time. Therefore, the stock level typically represents an initial value from which the pan fill level and number of open stations are determined. Thus, given a stock level of 42 for burgers, one possible result after rounding is that there are 5 open stations with a pan fill level of 8 for burgers.

The routine begins with step 160 in which a product type section pointer and a closure priority list pointer are preferably initialized to 1. The product type section pointer selects different product type sections 132 as shown in FIG. 4 . The product type section pointed to or selected by the product type section pointer is selected in step 162 , and each of the sides of the stations are polled to determine whether the storage location corresponding to the product type selected are open (active) or closed (inactive). The order of polling the storage locations is provided by the closure priority list, which is ordered in an increasing order of priority. Stated differently, those storage locations that have a higher priority of being closed are listed before those storage locations having a lower priority of being closed in the closure priority list. The number of storage locations to close is calculated in step 164 by subtracting the stock level from the total number of open storage locations for the given product type section. If the number of storage locations to close is a negative number in step 166 , none of the storage locations are closed and the product type section pointer is incremented in step 168 to point to the next product type section.

If the number of storage locations to close is a positive number in step 166 , the storage location indicated by the closure priority list pointer is polled in step 170 . If the polled location is open in step 172 , the storage location is closed in step 174 , and the number of storage locations to close is decremented in step 176 . However, if the storage location is not open in step 172 , the number of storage locations to close is decremented in step 176 , and the closure priority list pointer is incremented in step 178 . If the number of storage locations to close is equal to zero in step 180 , the product type section pointer is incremented in step 168 . However, if the number of storage locations to close is not equal to zero in step 180 , the routine returns to step 170 to select the next storage location to poll as indicated by the closure priority list pointer. Following step 168 , if the product type section pointer is not equal to 13 in step 182 , indicating that the routine has not been performed for each of the 12 product type sections, the routine returns to step 162 . However, if the product type section is equal to 13 in step 182 , the routine terminates.

Conversely, it is also possible that the demand for one or more food products exceeds the number of storage locations allocated to that food product given a maximum pan fill level for each of the storage locations. In this case, more than one storage location can be assigned to the same prepared food product, and transfers of the food product and the associated storage time can be made between each of these storage locations. Such a transfer is termed a “cross-transfer”, and is not ordinarily permitted during normal operation, but can be programmed in response to increased demand for a particular food product.

The pan fill level represents the desired quantity of food product to be prepared on a per-pan basis. In order to calculate the pan fill level, a food product per unit sale volume is preferably determined, which represents the quantity of a particular food product sold at a predetermined unit of sale volume. For instance, if the unit of sale volume is selected to be $500 and the quantity of hamburgers sold is 50 when the volume of sale is $500, then the food product per unit sale volume would be 50. It is anticipated that the food product per unit sale volume will be calculated by sampling actual data under different conditions, such as at different times of the day and different days of the week to establish an acceptable degree of statistical certainty.

The current activity level is then preferably established as a multiple of the unit of sale volume in dollars. Thus, if the current activity level is $2000, then the activity level is equal to 4 since the current activity level is four times the unit of sale volume, which is $500. The food product per unit sale volume is then preferably multiplied by the current activity level and the product is divided by the total number of open pans to yield the pan fill level. Therefore, with a food product per unit sale volume equal to 50, an activity level equal to 4, and the quantity of open pans equal to 2, the pan fill level would preferably be equal to 100.

Method of Operation

FIGS. 9A and 9B show flowcharts of a method for monitoring the status of a food product using the product status and transfer system formed in accordance with the present invention. Upon power-on of the product status and transfer system, all stations enter the active mode wherein all active indicators are illuminated, and all product status indicators are red indicating that the product pans are empty and require product in step 98 . The worker then cooks the food product, places the cooked product into the pan in step 100 , and places the pan into the station, which is preferably the holding station in step 102 . The worker selects the product status switch corresponding to the location in the station just filled until the corresponding product status indicator turns green in step 104 indicating that there is unexpired product in the location just filled. The timer then initiates the count of the storage time by counting down the hold time in step 106 in response to the product status indicator turning green. Preferably following power-on, steps 100 - 106 will be repeated via step 108 until a sufficient quantity of each of the different products offered for sale is cooked and available at the holding station.

The flowchart continues on FIG. 9B with step 110 , which determines whether the timer has counted down to zero. If the timer has counted down to zero, the corresponding product status indicators change to flashing slow red in step 112 indicating that the corresponding product has expired and is no longer of acceptable quality. The worker then discards the expired product in step 114 , and selects the corresponding product status switch until the corresponding product status indicator turns red in step 116 . The routine continues with step 118 , which determines whether cooked product is available, and if it is, the worker selects the transfer switch which triggers the product transfer routine to be performed in step 120 . When the transfer routine has been completed, the routine returns to step 110 . If cooked product is not available, the routine returns to step 100 and the worker cooks additional product.

If the timer has not counted down to zero in step 110 , the routine determines whether the timer has counted down to the hold time less the cook time in step 122 . If the timer has counted down to the hold time less the cook time, the corresponding product status indicators change from green to yellow in step 124 indicating that the hold time is within the duration of the cook time of expiring and that additional product must be cooked. The routine continues with step 126 wherein the worker removes product from the station and prepares it for sale to the consumer. If the last food product has been removed from a particular location in step 128 , the worker presses the corresponding product status switch and the corresponding product status indicator changes from green or yellow to red in step 130 indicating that the pan is empty and requires product. If cooked product is available in step 118 , the product transfer routine is performed in step 120 and the routine continues with step 110 . If cooked product is not available in step 118 , the routine continues with step 100 , which provides additional cooked product. If the last product has not been removed in step 128 , the routine continues with step 110 .

The display 18 shown in FIG. 4 includes a separate product type section 132 corresponding to each upper and lower pan combination found in the stations 12 , 14 , 16 . Thus, the display 18 includes twelve total product type sections 132 . Each product type section 132 includes a product name display 134 , the product status indicators 44 corresponding to each of the stations 12 , 14 , 16 and a pan fill level display 136 . It is to be noted that each product type section 132 preferably corresponds to upper and lower pan combinations in each of the stations 12 , 14 , 16 , which are located in the same place on the station 12 , 14 , 16 . For instance, the product type section 132 located in a first column and a first row of the display 18 corresponds to the upper and lower pan combinations in the first row and the first column of each of the stations 12 , 14 , 16 . Thus, the product described by the product name display 134 in the first row and first column on the display 18 , e.g., “Burg”, preferably corresponds to the product noted in the product label 46 in the first row and the first column on each of the stations 12 , 14 , 16 .

Similarly, the product status indicators 44 in each of the product type sections 132 on the display 18 correspond to their counterparts on each of the stations 12 , 14 , 16 and display the same status. For instance, the product status indicators 44 corresponding to the holding station 16 in the product type section 132 in the first column and the first row of the display 18 preferably correspond to the product status indicators 44 in the first column and the first row of the holding station 16 . Likewise, the product status indicators 44 in the product type section 132 located in the first row and the first column of the display 18 corresponding to the front counter station 12 , preferably correspond to the product status indicators 44 in the first row and the first column of the front counter station 12 . Within each product type section 132 there are two product status indicators 44 (upper and lower) for each station 12 , 14 , 16 . The upper product status indicator 44 preferably corresponds to the upper pan for that location in the station 12 , 14 , 16 , and the lower product status indicator preferably corresponds to the lower pan for that location in the station 12 , 14 , 16 .

Thus, the worker 30 responsible for cooking product at the holding station 16 can monitor the status of each of the products at each of the stations by looking at the display 18 . In addition, the product status indicators 44 in each of the product type sections 132 are arranged such that the priority for replenishing the food products in each of the corresponding stations preferably decreases from left to right. The product status indicators 44 corresponding to the holding station 16 are positioned the farthest to the left, followed by the product status indicators 44 corresponding to the front counter station 12 and the drive-through station 14 . Thus, the holding station 16 is to be refilled before the front counter station 12 , which is to be refilled before the drive-through station 14 . The pan fill level display 136 indicates the pan fill level for each product, which is the number of units of each product that should be prepared when new product is cooked.

The display 18 also includes an activity level switch 138 , a day part switch 140 and an alphanumeric display panel 142 for electronically displaying an activity level and a day part. The activity level is preferably stored in memory. The pan fill level for each of the twelve different products displayed in the product type sections 132 is a function of the activity level, which represents an overall rate of sale for all of the products. Therefore, if the activity level is increased, the pan fill level for each of the products may increase causing additional product to be cooked and ready to meet an increase in demand. The worker can manually adjust the activity level by depressing the activity level switch 138 until the desired activity level is displayed on the alphanumeric display panel 142 . The activity level can also be automatically adjusted as a function of the time, the day, promotional events, sales, and the like. A change in the activity level preferably causes changes in the pan fill level for each of the products independently. For example, when changing from activity level 1 to activity level 2 , the number of chicken sandwiches can be increased from 6 to 10 whereas the number of burgers can remain at 10 .

The day part switch 140 can be used to select a desired period of the day, such as morning, afternoon, early evening and late evening. The day part preferably affects the identity of the products shown in the product name displays 134 for each of the product type sections 132 . For instance, if the day part is set to morning, typical products shown in the product name displays 134 might be eggs, muffins, sausages, and the like. In contrast, if the day part is set to afternoon, the product name displays 134 might indicate such products as burgers, chicken sandwiches, fish sandwiches, and the like.

The day part can be manually modified by activating the day part switch 140 , which sequences through the possible values for the day part shown on the alphanumeric display 142 until the desired day part is obtained. The day part can also be automatically modified as a function of the time.

The display 18 includes a menu switch 144 , editing cursor switches 146 and an enter switch 148 , which enable the product name displays 134 , pan fill level displays 136 , and potential values for the activity level and day part to be entered and modified by the workers 28 , 30 using means well known in the art. An external terminal (not shown) can optionally be connected to the display 18 and used to modify, download and upload versions of operational software, variables, constants, data, and the like as well as editing any of the parameters associated with and/or displayed on the display 18 .

Circuit Board Level Block Diagram

FIG. 10 shows a circuit board level block diagram of the product status and transfer system 10 formed in accordance with the present invention. The product status and transfer system 10 preferably includes six station/worker interface boards (SWIB) 150 for each of the stations 12 , 14 . Three of the SWIB 150 correspond to the front of the front counter station 12 or drive-through station 14 , and three of the SWIB 150 correspond to the rear of the front counter station 12 or drive-through station 14 . The holding station 16 preferably requires only three SWIB 150 since the worker 30 accesses only one side of the holding station 150 . The SWIB 150 corresponding to each of the stations 12 , 14 , 16 is indicated by dashed lines surrounding sets of SWIB 150 bearing reference numerals corresponding to the stations 12 , 14 , 16 .

Each station/worker interface board 150 includes four sets of two product status switches 42 , two product status indicators 44 and one product label 46 corresponding to each of the four columns in the station 12 , 14 , 16 . Each station 12 , 14 also includes two active/transfer boards (ATB) 154 . Each ATB 154 has one active switch 34 , one active indicator 36 , one transfer switch 38 and one transfer indicator 40 . The holding station 16 preferably includes only one ATB 154 since only one worker 30 accesses the holding station 150 . Each station 12 , 14 , 16 also includes a station interface board (SIB) 152 electrically coupled to each of the three or six SWIB 150 , and one or two ATB 154 . Each of the SIB 152 are electrically coupled to a station control board (SCB) 156 , which is electrically coupled to a display board 158 .

Tables 2 A- 2 E are parts list for the display board (CDB), station control board (SCB), station interface board (SIB), station worker interface board (SWIB) and active transfer board (ATB), respectively, shown in the circuit board level block diagram of FIG. 10 .

Tables 3 A- 3 E are netlists for the display board (CDB), station control board (SCB), station interface board (SIB), station worker interface board (SWIB) and active transfer board (ATB), respectively, shown in the circuit board level block diagram of FIG. 10 . The netlists provide a listing of connectivity between components located on the circuit boards according to the reference designations corresponding to the components and pin numbers on the components shown in the schematic diagrams for each of the circuit boards.

Station/Worker Interface Board

FIG. 11 is a schematic diagram of the station/worker interface board (SWIB) 150 shown in FIG. 10 . The SWIB 150 includes serially-addressable ports PCF8574T U 1 , U 3 , U 4 , drivers UDN2982LW U 2 , U 5 , LED's LD 1 -LD 8 , 330 ohm resistors R 1 -R 16 , 4.7 k ohm resistors R 17 -R 19 , 0.1 uF capacitor C 1 , C 3 , C 4 and switches SW 1 -SW 8 . The LED's LD 1 -LD 8 correspond to the product status indicators 44 on the SWIB 150 , and the switches SW 1 -SW 8 correspond to the product status switches 42 on the SWIB 150 .

A connector J 1 provides electrical connection between selected signals on the SWIB 150 and the station interface board (SIB) 152 . The serially-addressable ports PCF8574T U 1 , U 3 , U 4 and the drivers UDN2982LW U 2 , U 5 enable control of the product status indicators 44 , and monitoring of the product status switches 42 via serialized data to and from the SIB 152 . Groups of two LED's and two switches, such as LED's LD 1 -LD 2 and switches SW 1 -SW 2 correspond to one column on one of the stations 12 , 14 , 16 . The 4.7 k ohm resistors R 17 , R 18 and R 19 are used to pull the corresponding signals up to VCC, and the 0.1 uF capacitors C 1 , C 3 , C 4 provide bypass capacitance for the SWIB 150 .

The connector J 1 for the SWIB 150 corresponding to the front of the station and the connector J 1 for the SWIB 150 corresponding to the rear of station are connected to a modular T-connector (not shown), such as those used for telephones. A front/back signal coupled to connector J 1 provides a unique address, which determines whether the corresponding SWIB 150 corresponds to the front or rear of the station. In the preferred embodiment, the pin on connector J 1 corresponding to the front/back signal on the front SWIB 150 is cut, and since the front/back signal is, pulled up to VCC on the SWIB 150 , this SWIB 150 corresponds to the front of the station. Similarly, the front/back signal on the SWIB 150 corresponding to the rear of the station is tied to ground, which indicates that this SWIB 150 corresponds to the rear of the station. Thus, the preferred embodiment is advantageous in that the front/back signal is not required for the SWIB 150 corresponding to the front of the station, which results in a significant reduction in the number of wires between the SWIB 150 and the SIB 152 .

Remapping of Product Status Switches

FIGS. 8D and 8E show the display 18 mounted facing the front of the holding station 16 and the rear of the holding station 16 , respectively. It is preferred that the position of a given product type section 132 on the display 18 spatially corresponds to one of the upper and lower tray combinations on the holding station 16 as shown by dashed lines A on FIG. 8D . Each of the upper and lower tray combinations includes the product status indicators 42 , product status switches 44 , product label 46 and upper and lower trays 48 . It is sometimes desirable to mount the display 18 facing the rear of the holding station 16 if, for instance, access to an ac outlet can only be obtained by doing so. When this is done, the product type sections 132 on the display no longer correspond spatially to the correct upper and lower tray combinations as shown by dashed lines B on FIG. 8E . However, by remapping the addresses of the serially addressable ports PCF8574T U 1 -U 3 the spatial correspondence shown in FIG. 8D can again be achieved. This remapping can be achieved through software in the operational program of the SIB 152 or the SCB 156 based upon a switch selected by the user to indicate whether the display 18 is mounted facing the front of the holding station 16 or the rear of the holding station 16 .

Active/Transfer Board

FIG. 12 is a schematic diagram of the active/transfer board (ATB) 154 . The ATB 154 includes connector J 1 , LED's LD 1 -LD 3 , 330 ohm resistors R 1 -R 3 and switches SW 1 -SW 3 . The switches SW 1 -SW 3 correspond to the active switch 34 A, for the front of the station, the active switch 34 B for the rear of the station and the transfer switch 38 , respectively. The LED's LD 1 -LD 3 correspond to the active indicator 36 A for the front of the station, the active switch 36 B for the rear of the station, and the transfer indicator 40 , respectively. The 330 ohm resistors R 1 -R 3 limit the series current seen by the LED's LD 1 -LD 3 , and the connector J 1 provides electrical connection between the ATB 154 and the SIB 152 . A serially-addressable port PCF8574A7 U 1 is electrically connected to and disposed between the connector J 1 and the switches SW 1 -SW 3 and LED's LD 1 -LD 3 . The serially-addressable port PCF85747 U 1 enables the SIB 152 to access each of the switches and LED's via a serial data and address stream.

Station Interface Board

FIG. 13 is a schematic diagram of the station interface board (SIB) 152 . The SIB 152 includes a microcontroller 80C32A U 1 , which monitors and controls the SIB 152 , the ATB 154 and the SWIB 150 . A serial data bus is pulled up to VCC using a 4.7 k ohm resistor pack RN 1 . Three sets of serial ports, which are electrically connected to three connectors J 3 -J 5 , enable the microcontroller 80C32A U 1 to monitor the product status switches 44 located on the SWIB 150 .

The combination of an 11.059 MHz crystal Y 1 and 30 pF capacitors C 11 , C 12 provide a clock signal to the microcontroller 80C32A U 1 . A reset circuit DS1833-10 provides a reset signal having the required rise time, fall time and duration to the microcontroller 80C32A U 1 . A serial interface MAX 232 U 2 and 10 uF capacitors C 7 -C 10 in electrical connection thereto, provide an RS-232 bidirectional serial interface between the microcontroller 80C32A U 1 on the SIB 152 and components on the station control board 156 via a connector J 2 .

A set of capacitors C 1 , C 2 , C 4 , C 5 provide bypass capacitance, and a 4.7 k ohm resistor R 1 -R 3 is used to pull corresponding signals up to VCC. An inverter 7406 U 10 is used to logically invert the reset signal before being applied to a memory device PSD813F U 8 , which provides external RAM and ROM for the microcontroller 80C32A U 1 . A set of LED's LD 1 , LD 2 provide a visual indication of the day part, and whether the microcontroller 80C32A U 1 is running, which is also provided to an optional warmer daypart temperature select board (not shown) via a connector J 6 . A set of 330 ohm resistors R 4 , R 5 are used to limit the series current seen by the LED LD 1 , LD 2 and inverters 7405 U5 provide the necessary drive current.

Connectors J 3 -J 5 provide electrical connection between signals on the SIB 152 and those on each of up to six SWIB 150 and two ATB 154 . A voltage regulator LM2575T-5.0 VR 1 , L 1 , diodes D 1 , D 2 , a 470 uF capacitor C 14 , a 220 uF capacitor C 15 , and a bridge rectifier CR 1 provide regulation of a 12 volt supply to a 5 volt VCC via a connector J 1 on the SIB 152 . A programmable read only memory (PROM) 24C164 U 4 provides additional permanent memory storage for the microcontroller 80C32A U 1 .

Station Control Board

FIGS. 14A and 14B are schematic diagrams for the station control board (SCB) 156 . The SCB 156 is substantially similar to the SIB 152 with the exception of an additional bank of serial PROM 24C164 U 6 , U 7 and a serial RAM PCF8570 U 15 , which provide additional external memory for the microcontroller 80C32 U 1 . A time-of-day clock PCF8583 U 14 in combination with a 32.768 KhZ oscillator Y 2 , a 0.1 uF capacitors C 29 , C 14 an 18 pF capacitor C 25 and a diode IN270 CR 5 provide a battery-backed time of day to the microcontroller 80C32 U 1 to permit, for instance, automated control of the day part and the activity level.

The schematic diagram for the SCB 156 continues on FIG. 14B with a decoder 74LS138 U 17 and a multiplexer 74LS251N U 18 , which provide address decoding and data directivity for three bidirectional serial channels provided by a set of serial interfaces MAX232 U 19 -U 21 , and 10 uF capacitors C 32 -C 47 which are electrically connected to connectors J 3 -J 8 . The connectors J 3 -J 8 then connect to J 2 on FIG. 13 of the SIB 153 . A connector J 11 on the SCB 156 provides electrical connection between signals such as the data bus on the SCB 156 and the display board 158 .

A connector J 2 provides a 12v ac power signal from the display board to ferrite beads FB 1 , FB 2 , a switch S 1 , a bridge rectifier CR 1 , 470 μF capacitors C 27 , C 28 , an LED LD 1 and a 1.43 k ohmn resistor R 2 , which convert the 12 v ac power signal to a 12 v dc power signal. The 12 v dc power signal is regulated down to 5 v dc by a voltage regulator LM7805CT VR 1 and a 10 μF capacitor C 31 . The 12 v dc power signal is also provided to the display board via a connector J 9 . The remaining components shown in FIGS. 14A and 14B and their associated functions and connectivity are substantially similar to those described above for the SIB 152 shown in FIG. 13 .

Display Board

The display board 158 is shown in FIGS. 15A-15L . The connector J 11 on the station control board 156 shown in FIG. 14A is coupled to a connector J 2 on the display board 158 shown in FIG. 15A , and provides the multiplexed address and data bus to decoders 74LS138 U 16 -U 18 , latches 74HCT574 U 13 , U 15 and a buffer 74HCT540 U 14 . The outputs of the buffer 74HCT540 U 14 are pulled up to VCC with a 10K ohm resistor pack RN 1 . These devices along with a transistor 2N7000 Q 1 and a 180 ohm resistor R 3 enable control of the displays and indicators located on the display board 158 shown in FIGS. 15C-15K , as well as a vacuum fluorescent display VFD 1 shown in FIG. 15A , by the station control board 156 . A set of 0.1 μF capacitors C 1 -C 18 provide bypass capacitance for the devices on the display board 158 .

The vacuum fluorescent display VFD 1 shown in FIG. 15A corresponds to the alphanumeric display 142 shown in FIG. 4 . Groups of four 14-segment displays LTP3784E DS 1 -DS 24 shown in FIGS. 15C-15H correspond to one product name display 134 shown in FIG. 4 . Each of the 14-segment displays LTP3784E DS 1 -DS 4 is capable of indicating two alphanumeric digits. The decoders, latches and buffer shown in FIGS. 15A and 15B are electrically connected to six 14-segment drivers ICM7243B U 1 -U 6 shown in FIGS. 15C and 15H . These drivers provide the signals required by the 14-segment displays LTP3784 DS 1 -DS 24 to display the identities of the different products sold. It is to be noted that there are twelve groups of four 14-segment displays LTP3784E DS 1 -DS 24 shown in FIGS. 15C and 15H , which correspond to the twelve product name displays 134 on FIG. 4 .

FIGS. 15I and 15K show the pan fill level display 136 and the product status indicators 44 located on the display 18 as shown in FIG. 4 . Twelve groups of two 7-segment displays LN524RA DS 25 -DS 36 correspond to the twelve pan fill level displays 136 shown in FIG. 4 . Likewise, groups 160 of eight LED's LD 1 -LD 100 correspond to the product status indicators 44 in each product type section 132 shown in FIG. 4 . For instance, LED LD 1 on FIG. 15I corresponds to the product status indicator 44 in the first column and upper first row in the front counter station 12 , and LED LD 2 corresponds to the product status indicator 44 corresponding to the first column and lower first row in the front counter station 12 . Six 7-segment display drivers ICM7228A U 7 -U 12 are electrically connected to the decoders, latches and buffer shown in FIGS. 15A and 15B , and provide signals required for the LED's LD 1 -LD 100 and the 7-segment displays LN524RA DS 25 -DS 36 to display the status and the pan fill levels for each product, respectively.

FIG. 16F is a schematic diagram of the activity level switch 138 , the day part select switch 140 , the menu switch 144 , the editing cursor switches 146 and the enter switch 148 shown in the lower portion of the display 18 on FIG. 4 . Each of the switches include two terminals interconnected in a column and row matrix and provided as signals via a connector J 1 to the buffer 74HCT540 U 14 and the latch 74HCT574 U 15 shown in FIG. 15A . The microcontroller 80C32 U 1 on the SCB 156 can readily determine which of the switches was selected by accessing the buffer and latch by means well known in the art.

Additional Embodiments

The product status indicators 44 may include a liquid crystal display (LCD) or light emitting diode (LED) display, which is used to display the current value of the storage time for the corresponding food product. The worker may then use the storage time to determine whether a particular action should be taken with respect to the corresponding food product, such as cooking replenishment product or discarding the product.

Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawing, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention.