JPS62275790A - Thin-film electromagnetic converter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention relates to a thin film electromagnetic transducer, and particularly to a thin film electromagnetic transducer provided in a card incorporating a semiconductor memory. Concerning vessels.

(Prior Art) In recent years, as the amount of information has increased, HEs that store large amounts of information have been developed. For this reason, attempts have been made to increase the amount of information stored in cards such as credit cards by incorporating semiconductor memories instead of magnetic stripes. In this case, the conventional method for transmitting and receiving signals between the semiconductor memory and the reading device is to bring terminals on the card side into contact with terminals on the reading device side. However, this method had problems with the reliability of artistic contacts. In order to solve this problem, a method has been proposed in which an electromagnetic transducer is provided on the card and signals are exchanged magnetically between the card and the reader without contact.

An example of this method is to provide an electromagnetic transducer consisting of a spirally formed thin film or sheet coil within the card.

By the way, when a card with a built-in semiconductor memory is used in place of a current card having a magnetic stripe, it is desirable that it can be used with current reading devices. In this case, the playback head used in current reading devices is
This type has a ring-shaped core with a part cut out and a signal detection coil wound around it. In order to detect signals efficiently, the magnetic flux flowing into the core from one end of the cut-out gap must be It is necessary to form a return path so that the liquid flows through the core without leaking to the outside and heads toward the other end of the void.

However, conventional electromagnetic transducers are those in which only a thin film coil or sheet coil is directly provided on a substrate within a card, and no forced return path for returning magnetic flux to the vicinity of this coil is formed. For this reason, when reading with current reading devices, the magnetic flux generated flows into the read head of the reading device, but a large proportion of it leaks out to the outside along the way.
In order to generate a signal with a predetermined amplitude in the detection coil wound around the reproducing head, a large electromotive force is required, which poses a problem of poor efficiency.

(Problems to be Solved by the Invention) The present invention provides a thin-film electromagnetic transducer on a substrate built into a card, and when reading information from a semiconductor memory built into the card, the problem with the conventional electromagnetic transducer is solved. This solves the problem of a high rate of magnetic flux leaking to the outside due to the return path not being formed, making it possible to efficiently retrieve information in the card's built-in memory even when using a conventional card reading device. The purpose is to provide a thin film electromagnetic transducer.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention forms a thin film made of a soft magnetic material on the surface of a substrate built into a card incorporating a semiconductor memory, A spiral thin film coil is formed on this thin film to construct a thin film electromagnetic transducer.

(Function) According to the above configuration, the magnetic flux generated at the center of the coil formed on the substrate is forcibly returned to the vicinity of this coil, so that the magnetic flux flowing into the read head of the reading device is It flows through the core and returns to the vicinity of the coil.

Therefore, there is little leakage of magnetic flux from the rad core to the reproducing device, and signals can be detected efficiently.

(Example) Hereinafter, an example of a thin film electromagnetic transducer according to the present invention will be described with reference to the drawings.

FIG. 1 shows the structure of an embodiment of the present invention. In the figure,
A thin film 2 of a soft magnetic material having high magnetic permeability is formed on a substrate 1 built into the card, and an insulating l1 is formed on this thin film 2.
13 are formed. A spirally wound thin film coil 4 is formed on this insulating film 3.
It is connected to a semiconductor memory (not shown) built into the substrate 1 via coil terminals 5a and 5b at both ends.

Next, the operation of this embodiment will be explained with reference to FIGS. 2 and 3. In FIG. 2, 6 is a magnetic flux generated by a signal current flowing through the coil 4, and a magnetic path as shown in the figure is formed between the thin films 2 having high magnetic permeability. and coil 4
The magnetic flux generated at the center forms a magnetic path that is forcibly directed toward the thin film 2 in this vicinity.

When the rad core 8 is placed above the N magnetism converter according to the present embodiment configured in this way, as shown in FIG. The generated magnetic flux 6 enters the head core 8. Since the magnetic flux 6 flowing through the head core 8 is directed toward the substrate 2 having high magnetic permeability, leakage of the magnetic flux 6 to the outside while flowing through the head core 8 is small. In other words, most of the magnetic flux 6 generated inside the coil 4 passes through the head core 8 and forms a bus heading toward the recording film 2, so that it efficiently passes through the four detection coils 7.

According to this embodiment, since the magnetic flux 6 generated at the center of the coil 4 passes through the RAD core 8 and goes to the high magnetic permeability film 2 for reproduction, the leakage of magnetic flux from the head core 8 is small, and the magnetic flux 6 that is built in the card is information in memory can be detected efficiently.

In this embodiment, a case has been described in which the coil 4 is formed on the high magnetic permeability thin film 2 via the insulating film 3. However, if the thin film 2 is formed of a material with high resistivity such as ferrite, the insulating film 3 The coil 4 may be formed directly on the thin film 2 without the need.

[Effects of the Invention] As described above, according to the present invention, a thin film of high magnetic permeability made of a soft magnetic material is formed on the surface of a substrate built into a card with a built-in semiconductor memory, and a spiral shape is formed on this thin film. Since a thin film coil is formed to constitute a thin film electromagnetic transducer, the leakage of magnetic flux from the rad core to reading and reproducing is small, and even when using a conventional card reading device, the data in the memory built into the card can be efficiently read. You can read the latest news.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the thin film electromagnetic transducer according to the present invention, and FIGS. 2 and 3 are schematic diagrams showing the operation of the thin film electromagnetic converter shown in FIG. 1. 1... Card-shaped substrate 2... Soft magnetic material film 4... Coil agent Patent attorney Norihiro Chika Hiroshi Uji

Claims (1)

[Claims] A thin film electromagnetic transducer characterized in that a thin film made of a soft magnetic material is formed on the surface of a substrate built into a card containing a semiconductor memory, and a spiral thin film coil is formed on this thin film.