Coin discrimination method

• US 5,568,854 A
• Filed: 10/04/1994
• Issued: 10/29/1996
• Est. Priority Date: 06/28/1991
• Status: Expired due to Term

• Current Assignee: Protel Incorporated (Inductotherm Group)
• Original Assignee: Protel Incorporated (Inductotherm Group)
• Inventors: Hayes, Stephen J., Gorman, Patrick R.
• Primary Examiner(s): BARTUSKA, FRANCIS JOHN
• Application Number:
  US08/317,796
• Time in Patent Office: 756 Days
• Field of Search: 194/318, 194/319, 194/317
• US Class Current: 194/318
• CPC Class Codes: G07D 2205/001 Reconfiguration of coin testing devices
• CPC Class Codes: G07D 5/08 Testing the magnetic or electric properties

Abstract

An electronic coin detector and method for sensing the presence of a valid coin and for providing an indication of the valid coin'"'"'s type. A coin is guided into position between a first set of inductor coils. The coin is then guided through a channel surrounded by a second inductor coil. A first oscillating signal is then fed to the first set of inductor coils and a second higher frequency oscillating signal is fed to a second inductor coil. An altered signal is then provided in response to the effect of the coin passing through the inductor coils. After the coin has passed adjacent one of the inductor coils, the inductor coils are fed a calibration signal to produce a calibrated signal. This calibrated signal is then used to scale the altered signal. The frequency, amplitude, and amplitude-time characteristics of the scaled altered signal for the first set of inductor coils and the second inductor coil are combined with prestored statistical variables corresponding to frequency, amplitude, and amplitude-time characteristic values of a sample of valid coins. The combined results are then compared to determine if the deposited coin is valid. If the coin is valid, the combined results are compared with the prestored statistical variables to determine the coin'"'"'s type.

Claims

1. A coin detection method comprising the steps of:

establishing a magnetic flux across a coin path by providing an oscillating signal;

passing a coin under test along the path;

detecting the change in energy loss caused by the movement of the coin under test along the path;

utilizing the change for the detection of an amplitude characteristic of the coin under test;

determining the change of the amplitude characteristic with time of the coin under test;

storing into memory a statistical variable determined from measurements of the amplitude-time characteristics of a plurality of coins of the same type as the coin under test;

determining for the coin under test a deviation value in relation to the stored statistical variable; and

providing a signal indicating acceptability of the coin under test if the deviation value is within a predetermined acceptable range.

2. A coin detection method comprising the steps of:

establishing a magnetic flux across a coin path by providing an oscillating signal;

passing a coin under test along the path;

detecting both the change in inductance and the change in energy loss caused by the movement of the coin under test along the path;

utilizing both changes for the detection of plural predetermined characteristics of the coin under test;

determining the time rate of change of at least one predetermined characteristic of the coin under test;

storing into memory statistical variables determined from measurements of the time rate of change of the at least one predetermined characteristic of a plurality of coins of the same type as the coin under test;

determining for the coin under test a deviation value in relation to all of the stored statistical variables; and

providing a signal indicating acceptability of the coin under test if the deviation value is within a predetermined acceptable range.

3. A coin detection method comprising the steps of:

establishing a magnetic flux across a coin path with the use of an oscillation signal provided to an induction coil, the coil having a surface extending along the path, the surface being disposed adjacent the path such that when the coin travels along the path the coin passes adjacent the coil;

passing a coin under test along the path;

providing an altered oscillation signal in response to the effect of a coin passing adjacent the inductor coil;

sensing the amplitude of the altered oscillation signal as a function of time;

storing into a memory statistical variables determined from measurements of the amplitude-time characteristics of a plurality of coins of the same type as the coin under test;

determining for the coin under test a deviation value in relation to the stored statistical variables;

comparing the deviation Value with a predetermined statistical value; and

accepting the coin under test if the deviation value is less than the predetermined statistical value.

4. A method of determining whether or not a coin being sampled is acceptable, the method comprising the steps of:

establishing a magnetic flux across a coin path with the use of an oscillation signal provided to an induction coil, the coil having a surface extending along the path, the surface being disposed adjacent the path such that when the coin travels along the path the coin passes adjacent the coil;

passing a coin being sampled along the path;

providing an altered oscillation signal in response to the effect of a coin passing adjacent the inductor coil;

sensing the amplitude of the altered oscillation signal as a function of time;

storing into a memory statistical variables determined from measurements of the amplitude-time characteristics of a plurality of coins of the same type as the coin being sampled;

determining for the coin being sampled a deviation value in relation to the stored statistical variables; and

providing an indication that the coin being sampled is acceptable if the deviation value is within a predetermined range.