Optical vend-sensing system for control of vending machine

• US 7,742,837 B2
• Filed: 01/22/2008
• Issued: 06/22/2010
• Est. Priority Date: 04/29/1998
• Status: Expired due to Fees

• Current Assignee: Automated Merchandising Systems Incorporated (Seaga Manufacturing Incorporated)
• Original Assignee: Automated Merchandising Systems Incorporated (Seaga Manufacturing Incorporated)
• Inventors: Spentzos, Kyriakos P., Hair, James M. III
• Primary Examiner(s): Crawford; Gene
• Assistant Examiner(s): Waggoner; Timothy R
• Application Number:
  US12/010,126
• Publication Number:
  US 20080121648A1
• Time in Patent Office: 882 Days
• Field of Search: 221/2, 221/7, 221/13, 700/236
• US Class Current: 700/236
• CPC Class Codes: G07F 11/04 in which magazines the articles are stored one vertically above the other
• CPC Class Codes: G07F 11/42 the articles being delivered by motor-driven means
• CPC Class Codes: G07F 9/02 Devices for alarm or indication, e.g. when empty; Advertising arrangements in coin-freed apparatus alarms or warning devices indicating the interruption of flow to be metered G07F15/10
• CPC Class Codes: G07F 9/026 for alarm, monitoring and auditing in vending machines or means for indication, e.g. when empty

Abstract

For ensuring that a vending machine motor will continue to operate until a product has descended through a vending space or an established time interval has elapsed, an optical beam is established across the vend space through which a product must drop. A change in beam intensity is detected. By preference infra red light is emitted at one focal point of an elliptical reflector, and detected at the other focal point. The light is emitted in pulses in the preferred embodiment, and the optical sensing system has automated calibration and error detecting functions.

Claims

1. A vending machine, comprising:

a front panel;

one or more product trays wherein at least one product tray includes a product dispensing mechanism configured to perform a vending operation by which a selected product stored on one of said one or more product trays is advanced over a front edge of said one or more product trays so as to initiate delivery of a product upon selection by a customer;

a product delivery path comprising a portion of space in said vending machine into which said selected product falls after being advanced beyond said front edge of said one or more product trays and through which said selected product freely falls, independent of a product lowering mechanism, into a customer accessible bin for retrieval by the consumer, said product delivery path having a front-to-rear depth which extends substantially between said vending machine front panel and said front edge of said one or more product trays on which products are stored;

an optical vend-sensing system placed within said vending machine below said one or more product trays but above a customer accessible area of said bin, said optical vend-sensing system being configured to sense when said selected product freely falls through said product delivery path;

said optical vend-sensing system comprises;

one or more emitters placed on a first side wall of said product delivery path and configured to emit electromagnetic radiation into a cross-section of said product delivery path,

at least two active electromagnetic radiation detectors placed on a second side wall of said product delivery path opposite the first side wall upon which said one or more emitters are placed, said at least two active electromagnetic radiation detectors being positioned across said product delivery path at a distance from said one or more emitters that is greater than said front-to-rear depth and configured to receive electromagnetic radiation emitted by each of said one or more emitters, said one or more emitters and said at least two detectors being positioned so as to create a detection zone that substantially extends across the front-to-rear depth of said product delivery path,

vend detection circuitry operatively connected to said at least two active electromagnetic radiation detectors and being configured to detect changes in said electromagnetic radiation caused by said selected product as it freely falls through said product delivery path and to generate a positive vend detection signal in response thereto; and

vending machine control circuitry operatively connected with said product dispensing mechanism of said one or more product trays and said vend detection circuitry, said vending machine control circuitry configured to cause said product tray dispensing mechanism associated with said selected product to activate vending operation upon an attempted customer purchase and to continue said vending operation until the positive vend detection signal is received from said vend detection circuitry or a predetermined secondary condition occurs in which no positive vend detection signal is received during a timeout period;

wherein said vending machine control circuitry implements a corrective action when positive vend detection signal from said vend detection circuitry has not been received and said predetermined secondary condition has occurred, said corrective action comprises maintaining a credit established by the customer to allow an alternative selection or to provide a refund.

2. The vending machine of claim 1, wherein said vend detection circuitry detects changes in said electromagnetic radiation caused by said selected product passing through said product delivery path by determining that said electromagnetic radiation received by said at least two active detectors has been temporarily reduced by a threshold amount.

3. The vending machine of claim 2, wherein said one or more emitters are concurrently operative.

4. The vending machine of claim 3, wherein said front panel is a transparent front.

5. The vending machine of claim 4, wherein the electromagnetic radiation emitted by said one or more emitters is modulated at a frequency selected to reduce interference from ambient light.

6. The vending machine of claim 5, wherein the electromagnetic radiation is modulated at a frequency higher than 120 Hz.

7. The vending machine of claim 4, wherein said vend detection circuitry includes an ambient light calibration circuit that accounts for current ambient light conditions in establishing said threshold amount.

8. The vending machine of claim 4, wherein said one or more emitters is a row of electromagnetic emitters, said row substantially extending the front-to-rear depth of said product delivery path.

9. The vending machine of claim 8, wherein said one or more emitters forming said row are positioned so as to permit detection of a narrowest selected product that falls through the delivery path.

10. The vending machine of claim 9, wherein said narrowest selected product is about 0-0.25 inches in width.

11. The vending machine of claim 8, wherein said front to back depth of said product delivery path is about 9 inches.

12. The vending machine of claim 11, wherein said row of emitters is about 9 inches long.

13. A vending machine, comprising:

a front panel;

one or more product trays wherein at least one product tray includes a product dispensing mechanism configured to perform a vending operation by which a selected product stored on one of said one or more product trays is advanced over a front edge of said one or more product trays so as to initiate delivery of a product upon selection by a customer;

a product delivery path comprising a portion of space in said vending machine into which said selected product falls after being advanced beyond said front edge of said one or more product trays and through which said selected product freely falls, independent of a product lowering mechanism, into a customer accessible bin for retrieval by the consumer, said product delivery path having a front-to-rear depth which extends substantially between said vending machine front panel and said front edge of said one or more product trays on which products are stored;

an optical vend-sensing system placed within said vending machine below said one or more product trays but above a customer accessible area of said bin, said optical vend-sensing system being configured to sense when said selected product freely falls through said product delivery path;

said optical vend-sensing system comprising;

at least one emitter of electromagnetic radiation directed into said product delivery path,

at least one reflector positioned within said vending machine to reflect the electromagnetic radiation emitted by said at least one emitter,

at least one detector of electromagnetic radiation arranged to receive at least a portion of said electromagnetic radiation emitted by the at least one emitter and reflected by said at least one reflector, the at least one emitter of electromagnetic radiation, the at least one reflector, and the at least one detector of electromagnetic radiation being arranged to create a vend detection zone within the product delivery path; and

vend detection circuitry operatively connected to said at least one detector and being configured to detect changes in said electromagnetic radiation caused by said selected product as it freely falls through said vend detection zone and to generate a vend detection signal in response thereto.

14. A glass-front vending machine, comprising:

a transparent front panel;

one or more product trays including a product dispensing mechanism configured to perform a vending operation by which a selected product stored on one of said one or more product trays is advanced over a front edge thereof so as to initiate delivery of a product upon selection by a customer;

a product delivery path comprising a portion of space in said vending machine having a front-to-rear depth which extends substantially between said vending machine transparent front panel and said front edge of said one or more product trays and into and through which said selected product freely falls into a customer accessible bin for retrieval by the consumer after being advanced beyond said front edge;

an optical vend-sensing system placed within said vending machine and configured to sense when said selected product freely falls through said product delivery path;

said optical vend-sensing system comprising;

one or more emitters placed on a first side of said product delivery path and configured to emit electromagnetic radiation into said product delivery path,

one or more electromagnetic radiation detectors placed on a second side of said product delivery path opposite the side upon which said one or more emitters are placed, said one or more electromagnetic radiation detectors being configured to receive at least a portion of said electromagnetic radiation emitted by each of said one or more emitters,

vend detection circuitry operatively connected to said one or more electromagnetic radiation detectors and being configured to;

(i) detect changes in said electromagnetic radiation caused by said selected product as it freely falls through said product delivery path; and

to (ii) generate a positive vend detection signal in response thereto,

an ambient light calibration circuit configured to adjust a detection threshold used by said vend detection circuitry configured to minimize interference from light originating from other than said one or more emitters; and

vending machine control circuitry operatively connected to said product dispensing mechanism and said vend detection circuitry, said vending machine control circuitry configured to cause the product tray dispensing mechanism associated with the selected product to activate a vending operation upon an attempted customer purchase and to continue said vending operation until the positive vend detection signal is received from said vend detection circuitry or a predetermined secondary condition occurs in which no positive vend detection signal is received during a timeout period;

wherein said vending machine control circuitry implements a corrective action when positive vend detection signal from said vend detection circuitry has not been received and said predetermined secondary condition has occurred, said corrective action comprises maintaining a credit established by the customer to allow an alternative selection or to provide a refund.

15. The vending machine of claim 14, further comprising a row of electromagnetic emitters extending across the front-to-rear depth of said product delivery path and creating a least one plane of electromagnetic radiation that spans a cross-section of said product delivery path and reaches said one or more electromagnetic radiation detectors.

16. The vending machine of claim 14, wherein said ambient light calibration circuit tests current ambient light conditions existing prior to a sale and resets the detection threshold to account for said current ambient light conditions.

17. The vending machine of claim 16, wherein the detection threshold is increased in response to increased ambient light conditions.