JPS58208883A - Ic card - Google Patents

Abstract

PURPOSE:To realize an IC card havig stabilized connection, by using a photoconnection for a signal transmission line which can easily cause malfunction due to level fluctuation and noise. CONSTITUTION:Light from LEDs 7 and 23 is modulated to transmit signals to opposite photodiodes 22 and 8. Since the carrier of the signal is light, the signal can be transmitted at high speed, and only one channel for transmitting and receiving is sufficient to perform a function. A miss transmission due to bad connection and noise due to vibration and sliding are not generated. Therefore, malfunction is hardly caused in comparison with a signal transmission using a contact. A signal to be transmitted to the photodiode 22 is obtained by converting a parallel signal transmitted to a serial interface circuit 6 from a signal processing part 2 to a serial signal in the serial interface circuit 6 to amplify its electric power and, thereafter, by transmitting it to the LED 7 to emit light.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an IC card having a stable coupling part.

An IC card is a card equipped with an integrated circuit such as a processor and a memory, and a backup battery for the memory, and is attached to a main body to send and receive signals to operate the main body.

Conventionally, the IC card and the main body have been connected by electrical contacts (hereinafter referred to as contacts). However, open contacts are easily contaminated and corroded by hand grime, harmful gases in the atmosphere, dust, etc. Contaminated or corroded contacts increase contact resistance and make it difficult for electrical signals to pass through, resulting in level fluctuations, and slight vibrations or sliding can cause contact resistance fluctuations, which can easily generate noise. In this case, even if a film is formed on the contact surface, if the applied current is large, the film will be electrically destroyed, so there is little problem, but in the case of IC cards where the MO8 circuit is weakened, the signal current It is weak and cannot electrically destroy the coating. For this reason, when connecting the IC card and the main body using contacts, signal voltage attenuation occurs due to increased contact resistance, contact resistance fluctuates due to slight vibrations, and noise corresponding to the vibration frequency is generated, resulting in malfunctions. It will come out if you do. In order to prevent such malfunctions, it is necessary to frequently clean the contact portions, which makes maintenance difficult. Conventional IC cards have these drawbacks and are not reliable enough.

This invention has been made in consideration of the above points, and utilizes the characteristics of the photocoupler and the contact to separate them, creating a structure in which malfunctions are less likely to occur at the joint. The present invention will be described in detail based on the following.

FIG. 1 shows an embodiment of the present invention.

In this figure, 1 is an IC card, 2 is a signal processing unit, and 3 is an IC card.
is a ROM, and 4 is a RAM. 5 is a thin battery, RA
Backing up M4. 6 is a serial interface circuit having an output section capable of driving LEDs; Photodiode 8 leads 9.1
0 are connected to the output section and input section of the interface circuit 6, respectively. The respective parts 2, 3, 4, 6) and 11, 12, 13 are connected to each other.

14°15 is the contact point, and lead @16.17,
Signal processing section 2. ROM3. It is connected to the power supply terminal of the serial interface circuit 6. And each of the above parts-
2-, 3, 4, 6, 7, and 8 are all constructed to be thin.

FIG. 2 shows a state in which the IC card 1 shown in FIG. 1 is attached to the main body 21. As shown in FIG. 22 is a photodiode for receiving light from the LED 7, and 23 is an LED for emitting light toward the photodiode 8. Contacts 24 and 25 are in contact with contacts 14 and 15 on the card side, and power is supplied from the main body 18 to the IC card 1 through these contacts.

The light emitted from the LEDs 7.23 is modulated and transmits a signal to each opposing photodiode 22.8. Since the carrier of this signal is light, the signal can be transmitted at high speed, and it can function as a channel. Moreover, unlike the conventional case where signals are transmitted through contacts, there is no transmission error due to poor contact, and no noise due to vibration or sliding. Therefore, compared to signal transmission through contacts, malfunctions are less likely to occur.

Note that the signal transmitted to the photodiode 22 is a parallel signal transmitted from the signal processing unit 2 to the serial interface circuit 6, which converts it into a serial signal, amplifies the power, and then transmits it to the LED 7 to cause it to emit light. It's something you get.

In conventional IC cards, the circuit mounted on the tower is a low power consumption circuit such as CMO8, so it is possible to operate the circuit with just the battery mounted on the tower, but this invention uses light to transmit signals. In this case, it is necessary to supply power from outside. This power is supplied by contacts 14.15 and 24.25. Contacts are also used in this invention, but since they are the path for supplying power, the current flowing through the contacts is thick (and the coating on the contact surface is easily destroyed (and is less susceptible to contamination). Since it only performs transmission, noise absorption measures such as connecting a capacitor between the positive and negative lines can be taken, making it less likely to cause malfunctions.Power is supplied by emitting light and receiving it with a solar cell. However, it is not efficient and the area occupied by the solar cell is large (which is disadvantageous in terms of implementation.However, when power is supplied through contacts 14, 15, 24, 25 as in this invention) The power loss in the contact part is negligible, and it does not take up much space, allowing the feeding part to be made compact.

LED7. Photodiode8. The arrangement of the contacts 14,15 may be as shown in FIG. In this case, since the light emitting section and the light receiving section are separated, there is an advantage that mutual interference between transmission and reception is reduced.

Note that when the ground wire is separated from the power line, another set of contacts may be provided separately from the power supply contacts. Further, in the above description, a serial interface is used for transmitting and receiving signals through one channel each, but a parallel interface may also be used. In this case, the LEDs 7.23 and photodiodes 8.22 are arranged in the same number as the number of bits constituting a byte. The LED 7.23 may also be another light emitter, such as a laser diode. Photodiode 8°22
Other light receivers such as a transistor or the like may also be used.

As explained above, this invention uses optical coupling in the signal transmission path that is prone to malfunction due to level fluctuations and noise, so the influence of level fluctuations and noise is reduced, and the use of optical coupling eliminates the need for Since contacts are used for power supply, the connecting part can be configured compactly. Even if contacts are used in the power supply path, the coating is easily destroyed by the current, and the circuit can also absorb noise, so there is no similar problem. That is, in the present invention, since there are four transmission paths that are rational in accordance with the characteristics of the signal and the power, there is an advantage that an IC card with stable coupling can be realized.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing an embodiment of the present invention, Fig. 2 is a side view showing a state in which an IC card having a coupling part of the present invention is coupled to the main body, and Fig. 3 is another arrangement of the coupling part. FIG. In the figure, 1 is an IC card, 2 is a signal processing unit, 3 is a ROM,
4 is a RAM, 5 is a battery, 6 is a serial interface circuit, T is an LED, 8 is a 7-otodiode, 9.10 is a lead, 1'1.1-in, 13 is a pass line, 14.15 is a contact, 16. 1T is a lead set, 21 is a main body, 22 is a photodiode, 23 is an LED, and 24.25 are contacts.

Claims (1)

[Scope of Claims] An IC card having a signal processing section, a storage section, and an interface section, comprising: a light emitting section connected to an output section of the interface section; a light receiving section also connected to an input section of the interface section; These light emitting parts also have electrical contacts for power supply connected to the power supply line of the interface part. 1. An RC card characterized in that a light receiving section and an electrical contact constitute a coupling section that transmits and receives signals to and from a main body through optical coupling, and supplies power using the electrical contact.