Paper currency recognition system
AssigneeInternational Currency Technologies Corporation
InventorHung-Ta Chen
Life of this patent
Estimating the term…
Abstract
A paper currency recognition system used in a money exchange machine includes a LED type transmitter unit and a phototransistor type receiver unit controlled by a CPU. The receiver unit also includes an N-channel MOSFET. When a variation in the induction or signal current from the receiver unit is detected, the CPU controls the MOSFET to let a part of the induction current be shunt to the MOSFET, enabling the value of the induction current to be regulated to a readable range, and at the same time drives a control chip of the receiver unit to regulate the LED driving current, keeping the light intensity of the LED within a constant value.
Claims5
A paper currency recognition system used in a money exchange machine and adapted to recognize the authenticity of the paper currency which has been inserted into the money exchange machine, the paper currency recognition system comprising:
- a transmitter unit,
- a receiver unit, and
- a CPU (central processing unit) controlling the operation of said transmitter unit and said receiver unit,
- wherein said transmitter unit comprises at least one LED (light emitting diode) adapted for emitting light onto the paper currency which has been inserted into the money exchange machine, and a control chip adapted for providing a driving current to drive said at least one LED,
- wherein said receiver unit comprises at least one phototransistor, which produces a signal current when induced by the light emitted from said at least one LED and reflected by the paper currency which has been inserted into the money exchange machine, and a MOSFET (metal-oxide-semiconductor field effect transistor), and
- wherein, when a variation of the signal current from said receiver unit is detected, said CPU controls said MOSFET to let a part of the signal current be shunted to said MOSFET, enabling the value of the signal current to be regulated to a readable range, and at the same time drives said control chip to regulate the LED driving current, keeping the light intensity of said at least one LED within a constant value.
Dependencies are inferred from the claim text.