JPH0710429Y2 - Non-contact ID card - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a non-contact type ID card used as an identification means of a specific person in an entrance / exit management device or the like.

[Prior art]

This type of ID card is used, for example, as shown in FIG.

That is, a read-only memory (RO) in which data for identifying a specific person is written in the contactless ID card (1).
M) (2) and a specific code generation processing unit (4) including a microprocessor (CPU) (3) for reading the contents, and an oscillation circuit (5) driven by the output from this processing unit (4) And a specific transmission frequency from this transmission circuit (5), for example, a specific code signal S repeatedly transmitted at 300 MHz is received by a transmission signal detection device (6) provided separately, and this is decoded to, for example, the entrance / exit. It is used by unlocking the locking device provided in the management device.

However, if the output of the specific code signal oscillated from the oscillation circuit (5) of the non-contact type ID card (1) is weak, the transmission signal is detected unless the ID card (1) is directly contacted with the oscillation signal detection device (6). In some cases, it is not possible to do so, and the characteristic of this type of card that is a non-contact type is diminished.

[Outline of device]

The present invention has been made in view of the above circumstances, and a specific code generation processing unit that inputs and outputs a specific code for identifying a specific person, and outputs a specific code signal connected to this processing unit. In the non-contact type ID card in which an oscillation circuit for attaching to an insulating substrate, a loop antenna provided on one surface of the substrate to supplement the oscillation force of the specific code signal, and one pole is the loop antenna The other pole is provided on the substrate on the side of the loop antenna on the side of the substrate, and a coupling capacitor for coupling the oscillation circuit and the loop antenna is provided by using the permittivity of the substrate. To greatly enhance the oscillation output, transmit it to the oscillation signal detector very efficiently, and operate the above detector reliably without losing the original non-contact detection function. With it, ID inexpensive to produce printed circuit board can maintain and improve the portability and convenience, such as the card, and handling is also intended to provide an easy non-contact ID card.

[Example of device]

An embodiment of the present invention will be described below with reference to FIGS. 2 and 3 in which the same parts as in FIG.

A loop antenna (7) having a predetermined length is connected to the oscillation circuit (5) connected to the specific code generation processing unit (4) via a coupling capacitor (8).

The length of the loop antenna (7) is a length obtained by dividing the wavelength λ (cm) calculated by the following equation by N (integer).

λ = V / F (1) where λ: wavelength (cm), V: electromagnetic wave propagation speed (cm / s)
ec), F; oscillation frequency (Hz). Now, for example, when the oscillation frequency F = 600 MHz, since it is ^{V = 3 × 10 10 cm /} sec, by substituting this into equation ^{(1), λ = 3 × 10 10/} 6 × 10 8 = 50 ( cm).

The most desirable is to form a loop of about λ / 2, that is, about 25 cm, but consider λ considering the portability of the ID card and the size of a business card that is actually used. A value divided by an integer, that is, λ / 4 = 12.5 cm, is used. When using an oscillation frequency of 600 MHz, a loop antenna (7) having a length of 12.5 cm is connected.

FIG. 3 shows an embodiment of a specific method of forming the loop antenna (7). In this embodiment, a conductive pattern (10) formed on one surface of a printed circuit board (9) is used.

The loop antenna formed by the conductive pattern (10) is connected to the oscillation circuit (5) by an electrostatic capacity using the dielectric constant of the printed circuit board (9) itself, that is, a coupling capacitor (8). The electrostatic capacitance C at this time is given by the following expression (2).

C = 0.0885 · εS / d (PF) (2) where d is the distance between the conductive patterns on both surfaces of the printed circuit board, S is the facing area, and ε is the dielectric constant. For example, the dielectric constant ε = 7,
Using d = 1.6 mm and S = 1 cm ² , C = 3.87 PF is obtained.

Although the loop antenna is formed by utilizing the conductive pattern of the printed circuit board in the above embodiment, the present invention is not limited to this, and the loop antenna may be separately formed of an appropriate material and attached to the surface of the card. The method of can be considered.

[Effect of device]

As described above, according to the present invention, a specific code generation processing unit for inputting and outputting a specific code for identifying a specific person, and an oscillation circuit connected to the processing unit for outputting a specific code signal. In the non-contact type ID card attached to an insulating substrate, a loop antenna provided on one surface of the substrate to supplement the oscillation force of the specific code signal, and one pole is the substrate on the loop antenna side. Since the other pole is provided on each of the substrates on the side relative to the loop antenna and a coupling capacitor that couples the oscillation circuit and the loop antenna by using the dielectric constant of the substrate is provided, the oscillation output of the specific code signal It is significantly strengthened and transmitted to the oscillation signal detection device very efficiently, and it is possible to operate the detection device without fail without losing the original non-contact detection function. , It is possible to maintain and improve the portability and convenience, such as ID card, inexpensive to manufacture a printed circuit board, is and having the effect of equal handling is easy.

[Brief description of drawings]

FIG. 1 is a block diagram showing the structure of a conventional non-contact type ID card, FIG. 2 is a block diagram showing the structure of the same non-contact type ID card according to the present invention, and FIG. 3 is the ID card according to the present invention. 2A is a plan view of the printed circuit board showing an example of a method of forming a loop antenna in FIG. 1A, and FIG. 1B is a cross-sectional view taken along the line AA of FIG. (1) …… Non-contact type ID card (4) …… Specific code generation processing unit (5) …… Oscillation circuit, (7) …… Loop antenna (8) …… Coupling capacitor (9) …… Printed circuit board (10) …… Conductive pattern

Claims (1)

[Scope of utility model registration request] 1. A specific code generation processing unit for inputting and outputting a specific code for identifying a specific person, and an oscillation circuit connected to the specific code generation processing unit for outputting a specific code signal. In a non-contact type ID card mounted on a rectangular printed circuit board, a starting end and a terminating end are provided at one corner of one surface of the printed circuit board and formed as a conductive pattern along the outer edge to generate an oscillation force of the specific code signal. A supplementary loop antenna is provided on the other surface of the printed circuit board at the starting end and the end facing portion of the loop antenna, respectively, and couples the oscillation circuit and the loop antenna by utilizing the inductivity of the printed circuit board. A non-contact type ID card, which is provided with a coupling capacitor for