Patent ID: 7565222

Claim:
A method of providing reasonable assurance of a completed vend of a vendible item in a vending machine comprising: a. placing a set of optical emitters at spaced apart locations on one side of a dispensing area of the vending machine, the emitters each having on and off states, and when in the on state, emitting optical energy of predetermined characteristics, and an emitter beam spread; b. placing a set of optical detectors at spaced apart locations on a generally opposite side of the dispensing area in the emitter beam spread for each emitter of the set, each detector having on and off states, the on state adapted for sensing of at least a threshold level of optical energy of said predetermined characteristics from a detector viewing angle including each emitter of the set; c. holding all the emitters in the off state for a time period, monitoring the state of all the detectors and if any detector indicates an on state generating an output signal to indicate a possible error condition; d. turning an emitter on for a time period, monitoring the state of all the detectors and if any detector does not indicate an on state, generating an output signal to indicate a completed vend; e. repeating steps c. and d. for each other emitter; f. communicating any output signal to a master controller of the vending machine.