KR20040067557A - Coin detector for use in a coin acceptor - Google Patents

Abstract

PURPOSE: A coin detector to be used in a coin acceptor is provided, which has high reliability and need a small area of installation. CONSTITUTION: A coin detector(24) is comprised in the inside of a coin acceptor(2) located behind a face panel(1). The coin detector comprises a frequency oscillation circuit, a frequency switching circuit and a CPU. The coin detector measures an inductance of a coin inserted into a track(211) of the coin acceptor, and determines a value and genuineness of the coin by comparing the measured inductance with a reference value stored in the CPU. An oscillation circuit assembly comprises two printed circuit boards(242) located on both sides of the track of the coin acceptor symmetrically, and the printed circuit boards are used in sensing the inductance of the coin by comprising a spiral coil(2411).

Description

Coin Detector for Coin Acceptors {COIN DETECTOR FOR USE IN A COIN ACCEPTOR}

The present invention relates to a coin acceptor, and more particularly, to a coin detector for use in a coin acceptor using a spiral coil to measure the inductance value for whether the coin has passed correctly.

Common vending machines and game machines usually have a coin acceptor that uses a coin detector to detect the authenticity and value of the coin entered. According to the prior art, the coin detector for this purpose has an inductor element consisting of a jar-shaped coil applied for measuring the inductance value of the coin. The inductor element mainly consists of iron, copper, nickel, aluminum or lead. When electrically connected, the inductor element generates an oscillation frequency that induces a magnetic field with some variety of coins. Dependent on the coefficient of the magnetic field according to the sensed coin material, an eddy current is generated indicating the strength of the coefficient of the coin's magnetic field. The inductance error of the jar-shaped coil is 5 to 10%. Jar-shaped coils tend to fail and tend to be affected by ambient temperature. Moreover, jar-shaped coils require a lot of installation space.

The present invention is achieved by providing a coin detector for use in a coin acceptor for eliminating the above drawbacks. The main object of the present invention is to provide a coin detector used in a coin acceptor having a high reliability. Another object of the present invention is to provide a coin detector for using a coin acceptor that requires less installation space. Another object of the present invention is to provide a coin detector for using a durable coin acceptor in use.

According to the present invention, the coin detector is composed of a frequency oscillation circuit, a frequency switching circuit, and a CPU (central processing unit). If a coin detector is installed inside the track of the coin acceptor behind the face panel, the coin detector measures the inductance value of the coin injected into the track of the coin acceptor passing through the coin slot of the face panel, and the coin authenticity and value. The measured inductance value is compared with the reference value stored in the CPU to determine. The oscillation circuit assembly consists of two printed circuit boards arranged symmetrically on two sides of the track of the two coin acceptors and having a spiral coil adapted to measure the inductance value of the coins passing therethrough.

1 is an exploded view showing a face panel and a coin acceptor according to the present invention.

2 is a cross-sectional view showing the assembly of FIG.

3 is an exploded view showing one printed circuit board for an oscillation circuit assembly in accordance with the present invention.

Figure 4 is an exploded view showing a replacement state of the printed circuit board according to the present invention

5 is a circuit diagram of a coin detector according to the present invention (I)

5A is a circuit diagram of a coin detector according to the present invention (II).

6 is an operational flowchart according to the present invention.

<Description of the symbols for the main parts of the drawings>

1: face panel 2: coin acceptor

11: coin slot 12: coin return slot

211: Track 22: Coin Exit

24: coin detector 2411: threaded coil

242: circuit board 2421: a thin layer of plastic coating

241: oscillation circuit assembly 2412: shunt resistor

2413: logic gate 243: frequency switching circuit

2431: Analog Multiplexer 2432: Capacitor

2433: resistance 2434: control port

244 CPU

1, 2, 3, 5 and 5A, a coin acceptor 2 is provided behind the face panel 1. The face panel 1 has a coin slot 11 at the top and a return slot 12 at the bottom. The coin acceptor 2 has a coin inlet 21 connected to the coin slot 11 of the face panel 1, the coin outlet 22 is connected to an external coin box (not shown), and a coin return passage 23 is connected to the return slot 12 of the face panel 1, the track 211 extends from the coin inlet 21 to the coin outlet 22 and the coin return passage 23, and the coin detector 24. ) Is installed inside the track 211 and passes through the coin slot 11 of the face panel 1 to detect the authenticity and value of the coin introduced into the coin inlet 21 and the coin outlet 22 or coin return. It is applied to selectively control the path of the track 211 reaching the passage 23. The coin detector 24 includes an oscillation circuit assembly 241 adapted to detect the inductance value of the coin passing through the track 211, a frequency switching circuit 243 having an analog multiplexer 2431 and a control port 2434. ) And a CPU 244 connected to the control port 2434 of the frequency switching circuit 243. Once the coin is inserted into the track 211, the oscillation circuit assembly 241 detects the inductance value of the coin and compares the inductance value with the reference value stored in the CPU 244 to determine the authenticity and value of the coin. Makes it possible to detect. Once the authenticity of the coin is verified, the coin detector 24 allows the coin to pass through the coin exit 22 to reach the external coin box. If the coin is rejected (validated as counterfeit), the operator can press the coin return button located on the face panel 1, enable the coin to move to the coin return passage 23 and the coin is then slot 12 Is returned).

The oscillation circuit assembly 241 consists of two printed circuit boards 242 symmetrically provided on the two opposing side walls of the track 211. Each printed circuit board 242 has a helical coil 2411 facing the track 211.

Referring to FIGS. 3 and 4, the spiral coil 2411 on the printed circuit board 242 may have a rectangular shape as shown in FIG. 3, or a circular shape as shown in FIG. 4. Moreover, a thin layer 2421 of plastic coating covers over the helical coil 2411 on the circuit board 242. Thin layer 2421 of plastic coating may be polycarbonate.

Referring again to FIGS. 5 and 5A, the oscillation circuit assembly 241 is composed of a spiral coil 2411, a shunt resistor 2412, and a logic gate 2413. The frequency switching circuit 243 includes an analog multiplexer 2431, a plurality of capacitors 2432, and a resistor 2433 connected to correspond to the analog multiplexer 2431, respectively. The resistor 2433 forms a control port 2434 connected to the CPU 244. Capacitor 2432 provides a series of oscillation frequencies to be selected by CPU 244 to be used according to a predetermined reference value.

Referring back to Figures 6 and 2, 3, 5 and 5A, the implementation of the present invention is based on the following steps.

Start (step 301).

Enter the standby mode (step 302).

The analog multiplexer 2431 of the frequency switching circuit 243 of the oscillation circuit assembly 241 switches the helical coil 2411 and sends a signal to the CPU 244 for storage and passes therein if no coin passes. Returns. When the spiral coil 2411 of the oscillation circuit assembly 241 detects an oscillation frequency through which coins pass, the oscillation circuit assembly 241 proceeds to step 304 (step 303).

After comparing the detected oscillation vibration of the coin with the reference value stored in the CPU 244 and determining the authenticity of the coin, if the authenticity of the coil is verified, proceed to step 305 or, if the coin is forged, proceed to step 306 ( Step 304).

When the coin exit 22 is opened and the coin is input, the process returns to step 302 (step 305).

The counterfeit coin is returned to the coin return slot 22 (step 306).

As described above, the present invention has the following advantages.

1. High stability: The oscillation circuit assembly consists of two printed circuit boards provided symmetrically on the wall of two opposite sides of the track, so that the distance between the detected spiral coil and the coin is minimal and the track Due to the helical coil provided symmetrically on two sides of the oscillation circuit assembly, the oscillation circuit assembly reliably detects the inductance frequency through which the coin passes.

2. Easy installation: The printed circuit board of the oscillation circuit assembly can be easily installed on both sides of the track inside the coin acceptor. The printed circuit board of the oscillation circuit assembly is robust and the printed circuit board is thin, eliminating the need for multiple maintenance tasks.

3. High accuracy: The inductance error of the spiral coil of the oscillation circuit assembly is within 0.1%, achieving high accuracy.

One embodiment of the coin detector used in the coin acceptor is achieved in the shape of FIGS. The coin detector for use in the coin acceptor works smoothly to provide all the cases discussed above in shape.

Although only specific embodiments in accordance with the present invention have been described for purposes of explanation in detail, various modifications and improvements can be made without departing from the spirit and scope of the present invention. Accordingly, the invention is not limited except as by the appended claims.

Claims (8)

In the coin detector provided in the track of the coin acceptor located behind the face panel, The coin detector consists of a frequency oscillation circuit, a frequency switching circuit, and a central processing unit (CPU). The coin detector measures an inductance value of a coin introduced into the track of the coin acceptor through the coin slot of the face panel. Compare the inductance value with the reference value stored in the CPU to determine the authenticity and value of the coin, wherein the oscillation circuit assembly consists of two printed circuit boards symmetrically located on both sides of the track of the coin acceptor The circuit board has a spiral coil facing each other and is applied to detect the inductance value of the coin passed. The coin detector of claim 1, wherein the spiral coil has a right angle shape. The coin detector of claim 1, wherein the helical coil is circular. The coin detector of claim 1, wherein the oscillation circuit further comprises a logic gate and a shunt resistor. The coin detector of claim 1, wherein the frequency switching circuit comprises an analog multiplexer, a plurality of capacitors, and a resistor respectively connected to the analog multiplexer. The coin detector of claim 5, wherein the resistor forms a control port connected to the CPU. 2. The coin detector of claim 1, wherein the printed circuit board of the oscillation circuit further comprises a thin layer of plastic coating covering respective spiral coils. 8. The coin detector of claim 7, wherein the thin layer of plastic coating is formed of polycarbonate.