JPS6232835B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic card reading device configured so that a magnetic head for detecting card insertion and a magnetic head for reading magnetically recorded contents can share the same amplifier.

For example, in recent years, automatic teller machines have become commonplace in banks and the like, and in most of these machines, cash transactions are carried out using magnetic cards as an intermediary. Therefore, although such a device is equipped with a magnetic card reading device therein, it has the disadvantage that an amplifier is required for each magnetic head prepared for each purpose.

FIG. 1 shows the configuration of a magnetic card reader according to the prior art, which requires an amplifier to accommodate the magnetic head.
That is, the magnetic head 1 for detecting card insertion (first magnetic head) and the magnetic head 2 for reading magnetically recorded contents (second magnetic head) each require amplifiers 3 and 4, respectively. In this case, the magnetically recorded contents are read after the card insertion is detected, so amplifiers 3 and 4 do not function as amplifiers at the same time, and the card insertion detection method is to read the magnetically recorded data. Considering that this is done simply by counting the number of magnetization reversals, it is clear that it is not preferable to provide an amplifier for detecting card insertion and for reading the contents of magnetic recording from the viewpoint of the number of parts and circuit configuration. be.
For this reason, it has been conventionally considered to have the amplifier 4 also have the function of the amplifier 3. A mechanical switching contact is inserted in series in each of heads 1 and 2, and heads 1 and 2 are connected in parallel via these mechanical switching contacts, and then connected to amplifier 4. By controlling the opening and closing of the heads 1 and 2, the outputs from the heads 1 and 2 can be amplified by the same amplifier 4 at different times.

However, when attempting to share an amplifier using mechanical switching contacts, a new problem arises. This is because mechanical contacts generally have low contact reliability, and the contact resistance value varies widely, so the output of heads 1 and 2 may be extremely low, such as when the output voltage is less than 100 mV. This is because if it is weak, it will be inappropriate for head switching.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a magnetic card reading device in which both heads can share the same amplifier without using mechanical contacts.

For this purpose, the present invention uses an analog switch whose impedance is extremely large when off and extremely small when on, and further ensures reliable switching of the analog switch. It is.

The present invention will be explained below with reference to FIGS. 2 and 3.

FIG. 2 shows the configuration of an example of a magnetic card reading device according to the present invention. As shown in the figure, the main difference from the one shown in FIG. They are connected in parallel via analog switches 5 and 6, and then connected to the amplifier 4. Control is performed so that only analog switch 5 is turned on when head 1 detects card insertion, and only analog switch 6 is turned on when head 2 reads magnetically recorded content. For example, the output voltages of heads 1 and 2 are sequentially amplified by amplifier 4 at different times. Therefore, if the insertion position of the card is detected and the analog switches 5 and 6 are controlled on/off appropriately according to the detection output, after the insertion of the card is detected by the single amplifier 4 as desired. , the contents of the magnetic recording are read.

The entry position of the card can be detected, for example, photoelectrically. As shown in FIG. 3, when the card 9 is inserted, the card 9 is first automatically transferred in the direction of the arrow through the area directly below the head 1, and then transferred to the right through the area directly below the head 2. However, for example, during the period when the card 9 exists directly under the head 2, the phototransistors 10 to 1 arranged in the relationship as shown in the figure
2. It is detected by light emitting diodes 13 to 15. When the card 9 is located directly below the head 2, at least the phototransistors 10 to 12
Since any one of them is turned on, the analog switches 5 and 6 are turned off and on, respectively, when one of them is turned on. In some cases, the analog switches 5 and 6 are turned on and off, respectively. Since the phototransistor 10 is placed between the heads 1 and 2, it is possible to detect in advance the approach of a card to the head 2, and its output signal can be used to keep the analog switch 6 in the ON state in advance. It is possible to compensate for the delay in the start-up of the operation, which is a drawback.

Furthermore, since the phototransistor 12 is placed at a distance from the head 2 in the transport direction by more than the length of the magnetic card, the connection between the head 2 and the amplifier 4 is severed while the card passes directly under the head 2. Never. When the phototransistor is turned on, a so-called low level output is obtained from the phototransistor, but phototransistor 1
With the output from 0 to 12, analog switch 5,
6 is easy to control on and off. The outputs A to C obtained from the phototransistors 10 to 12, respectively, are input to the NAND gate 8, and the outputs of the NAND gate 8 are used to switch the analog switch 5.
Furthermore, the analog switch 6 is controlled on/off by the output of the NAND gate 8 via the inverter 7.

In this example, the analog switches 5 and 6 are assumed to be DG200BA manufactured by Siliconix. This is a single-sealed analog switch with two single-function analog switches enclosed in one can-sealed package.
Off control can be performed directly using the TTL logic gate output, and the resistance value in the on state is extremely low and in the off state it is extremely large, making it ideal for head switching. . A description of the configuration of the analog switches 5 and 6 will be omitted, but when the logic level input is low level (0.8 V or less) or high level (2.4 to 5 V), the analog switches are turned on and off, respectively. . Therefore, in the case shown in FIG. 2, the analog switch 5 is normally in the on state, but is in the off state only during the period of reading the magnetic recording contents, and on the contrary, the analog switch 6 is normally in the off state. However, it is turned on only during the magnetic recording content retrieval period. In short, the desired purpose can be achieved by turning on only the analog switch 5 during the period of detecting the insertion of the card, and turning only the analog switch 6 on during the period of reading the magnetically recorded contents. .

Although the present invention is as described above, it goes without saying that it can also be applied to a case where there are three or more heads if the reading timings are different. However, when multiple heads share an amplifier, the outputs obtained from the amplifiers need to be properly processed and then discriminated.

As explained above, the present invention involves inserting and connecting analog switches in series to the magnetic head for detecting card insertion and the magnetic head for reading magnetic recorded contents, respectively.
By connecting these heads in parallel and connecting them to a single amplifier, we ensured that both heads were switched based on the signals from the elements that detected card movement in advance, allowing us to use an analog switch. It is possible to perform switching operations reliably while compensating for the operating characteristics of .

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of a magnetic card reading device according to the prior art, FIG. 2 is a diagram showing the configuration of an example of the magnetic card reading device according to the present invention, and FIG. 3 is a diagram showing the detection of the card entry position. FIG. 3 is a diagram illustrating an example of the mechanism in relation to a magnetic head. 1...Magnetic head for card insertion detection, 2...Magnetic head for reading magnetically recorded contents, 4...Amplifier,
5, 6...Analog switch.

Claims (1)

[Scope of Claims] 1. After the insertion of the card is detected by the magnetic card being transported sequentially passing through a first magnetic head for detecting card insertion and a second magnetic head for reading magnetically recorded contents, In a magnetic card reading device configured to read magnetically recorded contents on the card, an analog switch is inserted and connected in series to each of the first and second magnetic heads, and the heads are connected in parallel via the analog switch. Then, it is connected to the same amplifier, and the magnetic card is placed near the magnetic card transfer path from the time when the magnetic card passes through the first magnetic head and approaches the second magnetic head until it finishes passing directly under the second magnetic head. A detection element group consisting of a plurality of detection elements arranged to detect the period is arranged, and only the second magnetic head is connected to the amplifier based on the detection of the presence of the magnetic card of the detection element group. , a magnetic card reading device configured to control one of the analog switches to be in an on state based on an output signal of the detection element group so as to connect the first magnetic head to the amplifier at all other times. 2. The detection element group is located between the first magnetic head and the second magnetic head, in the vicinity of the second magnetic head, and at positions at least the length of the magnetic card in the transport direction from the second magnetic head. Claim 1 consisting of three elements arranged respectively.
The magnetic card reading device described in Section 1.