CAPACITIVE SENSING SYSTEM FOR THE DETECTION OF FOOD PRODUCTS DISPOSED WITHIN A FOOD WARMING TRAY OR FOOD STORAGE CONTAINER

Abstract

A capacitive sensing system for the detection and quantification of food products disposed within a food warming drawer or food storage container is disclosed and comprises an electrically grounded metal plate, and a printed circuit board (PCB) having a plurality of capacitive sensing pads disposed thereon and which effectively serve as capacitive sensors capable of detecting and measuring the capacitance of an object in proximity to it. The system, in conjunction with known detection circuitry, outputs or generates digital number signals which are indicative of the capacitance of the items or food products disposed within the food warming drawer or storage container. The system can therefore be utilized to detect the presence and number of food items disposed within the food warming drawer or container, as well as whether or not the food items are disposed within a vertically stacked array or disposed in a side-by-side array. The system is adapted to be utilized within the food industry as a means for knowing how many food items are present and ready to be used to fulfill patron food orders.

Claims

1. A capacitive sensing system for detecting and quantifying the presence of items, comprising: an electrically grounded metal plate; a printed circuit board; and a plurality of capacitive sensing pads, disposed upon a surface portion of said printed circuit board which faces, or is disposed toward, the items to be detected and quantified, so as to define, together with said electrically grounded metal plate, a capacitive sensing system which is capable of measuring the capacitance of one or more items in proximity to said plurality of capacitive sensing pads and thereby detect the presence of the one or more items and to quantify the number and size of the one or more items.

2. The system as set forth in claim 1, wherein: the items comprise food items.

3. The system as set forth in claim 2, wherein: the items comprise food items which are disposed within a food storage container.

4. The system as set forth in claim 3, wherein: said food storage container comprises a food warming drawer or food warming tray for maintaining the food items warm while patron food orders are processed and fulfilled.

5. The system as set forth in claim 1, wherein: each one of said plurality of capacitive sensing pads outputs a signal, in the form of a digital number, which is representative of the capacitance of the item which is in the proximity of one or more of said plurality of capacitive sensing pads, whereby the presence of the item, as well as its size or dimensions, can be determined as a result of said signal outputs from said plurality of capacitive sensing pads.

6. The system as set forth in claim 5, wherein: said plurality of capacitive sensing pads can detect the presence, size, and thickness dimensions of the items when the items are disposed within a side-by-side array.

7. The system as set forth in claim 5, wherein: said plurality of capacitive sensing pads can detect the presence, size, and thickness dimensions of the items when the items are disposed within a vertically stacked array.

8. The system as set forth in claim 1, wherein: said plurality of capacitive sensing pads are fabricated from a material selected from the group comprising copper, indium tin oxide (ITO), electrically conductive composites, and printed ink.

9. The system as set forth in claim 1, further comprising: a memory for storing therein predetermined capacitance levels indicative of different items such that when capacitance levels are detected by said capacitive sensing system, the number, size, and location of the items can be detected and quantified by said system.

10. The system as set forth in claim 1, further comprising: a display for displaying to food order or food service personnel the number of items detected.

11. Food equipment having a capacitive sensing system incorporated therein for detecting and quantifying the presence of items, wherein said system comprises: an electrically grounded metal plate; a printed circuit board; and a plurality of capacitive sensing pads, disposed upon a surface portion of said printed circuit board which faces, or is disposed toward, the items to be detected and quantified, so as to define, together with said electrically grounded metal plate, a capacitive sensing system which is capable of measuring the capacitance of one or more items in proximity to said plurality of capacitive sensing pads and thereby detect the presence of the one or more items and to quantify the number and size of the one or more items.

12. The equipment as set forth in claim 11, wherein: the items comprise food items.

13. The equipment as set forth in claim 12, wherein: the items comprise food items which are disposed within a food storage container.

14. The equipment as set forth in claim 13, wherein: said food storage container comprises a food warming drawer or food warming tray for maintaining the food items warm while patron food orders are processed and fulfilled.

15. The equipment as set forth in claim 11, wherein: each one of said plurality of capacitive sensing pads outputs a signal, in the form of a digital number, which is representative of the capacitance of the item which is in the proximity of one or more of said plurality of capacitive sensing pads, whereby the presence of the item, as well as its size or dimensions, can be determined as a result of said signal outputs from said plurality of capacitive sensing pads.

16. The equipment as set forth in claim 15, wherein: said plurality of capacitive sensing pads can detect the presence, size, and thickness dimensions of the items when the items are disposed within a side-by-side array.

17. The equipment as set forth in claim 15, wherein: said plurality of capacitive sensing pads can detect the presence, size, and thickness dimensions of the items when the items are disposed within a vertically stacked array.

18. The equipment as set forth in claim 11, wherein: said plurality of capacitive sensing pads are fabricated from a material selected from the group comprising copper, indium tin oxide (ITO), electrically conductive composites, and printed ink.

19. The equipment as set forth in claim 11, further comprising: a memory for storing therein predetermined capacitance levels indicative of different items such that when capacitance levels are detected by said capacitive sensing system, the number, size, and location of the items can be detected and quantified by said system.

20. The equipment as set forth in claim 11, further comprising: a display for displaying to food order or food service personnel the number of items detected.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Various other features and attendant advantages of the present invention will be more fully appreciated from the following detailed description when considered in connection with the accompanying drawings in which like reference characters designate like or corresponding parts throughout the several views, and wherein:

[0009] FIG. 1 is a schematic view the new and improved capacitive sensing system, as developed in accordance with the principles and teachings of the present invention, which may be employed for detecting or determining the presence of various objects, such as, for example, food products, their size, their number, and their location within a food warming tray or food storage container, by detecting and measuring the capacitance of the food products which are disposed within a predetermined proximity to a printed circuit board having a plurality of capacitive sensing pads formed thereon; and

[0010] FIG. 2 is a schematic view of the printed circuit board having the plurality of capacitive sensing pads disposed thereon which effectively define a plurality of capacitive sensors wherein each sensor will emit a signal, in the form of a digital number, representing the capacitance of the food product within its vicinity or proximity whereby the food products, and their number, can be detected and counted, regardless of whether the food items are disposed in a side-by-side array with respect to each other, or are disposed within a stacked array wherein the food items are disposed one atop another.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0011] Referring now to the drawings, and more particularly to FIGS. 1 and 2 thereof, a new and improved capacitive sensing system, developed in accordance with the principles and teachings of the present invention, and is intended to be utilized in connection with the detecting and measuring the capacitance of, for example, food products disposed within a food warming tray or a food storage container, is disclosed and is generally indicated by the reference character 100. More particularly, as can best be seen or appreciated from FIG. 1, the new and improved capacitive sensing system 100 is adapted to be disposed within a warming drawer or food product storage container disposed within, or adjacent to, food cooking apparatus or equipment 101 and is seen to comprise an electrically grounded metal plate 102, which effectively serves as a floor or bottom wall of a food warming tray or food storage container 104 within which a plurality of food items 106 are disposed, and a printed circuit board (PCB) 108 having a plurality of capacitive sensing pads 110 etched thereon as seen in FIG. 2.

[0012] With reference being made to FIG. 2, it is seen that the printed circuit board (PCB) 108 comprises, for example, a rectangularly configured printed circuit board (PCB) 108 which has a plurality of rectangularly configured capacitive sensing pads 110 etched onto an interior surface 112 of the printed circuit board (PCB) 108, that is, upon the surface which effectively faces, or is oriented toward, the food items 106 to be sensed and measured. The plurality of rectangularly configured capacitive sensing pads 110 are disposed parallel to each other and are disposed, within a linear array, adjacent to one another such that each one of the plurality of rectangularly configured capacitive sensing pads 110 has its oppositely disposed, short sides disposed opposite to, and adjacent to, the long sides of the rectangularly configured printed circuit board (PCB) 108, while the oppositely disposed, long sides of the two rectangularly configured capacitive sensing pads 110, disposed upon opposite ends of the linear array of the plurality of rectangularly configured capacitive sensing pads 110, are disposed parallel to the short sides of the printed circuit board (PCB) 108.

[0013] Reverting back to FIG. 1, it is seen that the food items 106 are disposed upon the electrically grounded metal plate 102 whereby the electrically grounded metal plate 102 effectively cooperates with the plurality of capacitive sensing pads 110, which are disposed upon the printed circuit board (PCB) 108 and effectively define capacitive sensors, so as to define with the plurality of capacitive sensing pads 110, capacitive coupling circuits which can effectively detect the presence of items, the size of the items, and the location of the items, which are effectively located at positions interposed between the plurality of capacitive sensing pads 110 and the electrically grounded metal plate 102, as a result of detecting and measuring the capacitance of the objects in proximity to each one of the plurality of capacitive sensing pads 110. The plurality of capacitive sensing pads can be fabricated from a variety of materials, such as, for example, copper, indium tin oxide (ITO), electrically conductive composites, and printed ink. In addition, it is to be noted that a data memory 114 is operatively associated with the food cooking apparatus or equipment 101, or alternatively with the food warming tray or food storage container 104, whereby predetermined capacitance levels, characteristic of individually different cooked food items, such as, for example, hamburgers, French fries, pancakes, egg breakfast sandwiches, and the like, are stored as base capacitance levels indicative of the individual food items. Still further, a display 116, likewise operatively associated with the food cooking apparatus or equipment 101, or alternatively with the food warming tray or food storage container 104, is provided so as to display to food order or service personnel the number of food items 106 disposed within the food warming tray or food storage container 104.

[0014] Having described substantially all of the structural components comprising the new and improved capacitive sensing system 100 of the present invention, the operation of the same will now be briefly described. More particularly, in operation, when one or more foods items 106 are disposed within the food warming drawer or food storage container 104, and the system 100 is activated, the system 100, in conjunction with known detection circuitry, will output digital numbers, one per capacitive sensor or capacitive sensing pad 110, which respectively represent the capacitance of the object or objects in proximity to each one of the plurality of capacitive sensing pads 110 in accordance with the stored capacitance data within memory 114 which is indicative of the capacitance of a particular food item 106. Therefore, by utilizing a sufficient number of capacitive sensors or sensing pads 110, a multiplicity of food products 106 can be detected and counted, regardless of whether the food products 106 are disposed in a side-by-side array with respect to each other, as illustrated within the left side portion of FIG. 1, or stacked atop one another as illustrated within the right side portion of FIG. 1. The digital numbers outputted by means of the system 100 may then be represented as a waveform from which the data may be analyzed by means of a suitable software algorithm so as to yield the number of food items 106, their size or thickness dimensions, and their locations within the food warming tray or food storage container 104. The number of food items 106 detected is then displayed to food order or food service personnel upon the display 116. It is lastly noted that the printed circuit board (PCB) 108 can be a relatively hard or rigid board, or alternatively, the printed circuit board (PCB) can be a relatively flexible printed circuit board (PCB) so as to enable the system of the present invention to be utilized within additional environments as may be necessary. For example, a flexible printed circuit board (PCB) 108, having the plurality of capacitive sensing pads 110 mounted or defined thereon, could effectively be wrapped around a tubular pipe which is closed at both ends, and yet, objects disposed internally of the tubular pipe could be detected and quantified.

[0015] Obviously, many variations and modifications of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described herein.

REFERENCE NUMBER KEY

[0016] 100Capacitive sensing system [0017] 102Electrically grounded metal plate [0018] 104Food warming tray or food storage container [0019] 106Food items disposed within the food warming tray or food container [0020] 108Printed circuit board [0021] 110Plurality of capacitive sensing pads disposed upon printed circuit board [0022] 112Interior surface of printed circuit board [0023] 114Memory of system 100 [0024] 116Display of system 100