JP2789891B2 - Millimeter wave information reading system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a millimeter-wave information reading system for performing non-contact entry / exit management using, for example, a card.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 58-151722 proposes a system in which a host having an oscillator in a microwave band and a card having no oscillator are combined as a system for reading information in a non-contact manner using radio waves. ing. This method uses a part of the power of the response request signal from the host as a carrier for return, modulates it with information data inside the card, and returns it.The host demodulates the information data from this return wave, It reads the information written inside.

[0003]

However, in the conventional system, the wavelength of the microwave is several cm to several tens cm.
Therefore, if an attempt is made to reduce the size of the antenna on the host side, the directivity of the antenna cannot be sharpened, resulting in a system having characteristics close to non-directionality.

In this case, as a method of reading information from a card without a microwave oscillator, a method of using a part of the received power on a return carrier wave on the card side and performing modulation in the card or with an antenna has to be adopted. Therefore, a modulator, a memory, a battery, and the like are required in the card, so that the card is thick, expensive, and has a short life.

Further, in this case, since both the transmission antenna on the host side and the retransmission antenna on the card side are almost non-directional, the microwave transmission loss is large. Therefore, if the reading distance is to be increased, the radiated power from the host must be increased. Must. However, in consideration of the influence on the human body, there is a problem that the increase in radiated power is limited, and as a result, the detection distance cannot be extended.

The present invention solves the above problems,
It is an object of the present invention to provide a system for reading information that is non-contact and has a long reading distance by using a small-sized, inexpensive and long-life card while reducing the size of the antenna on the host side.

[0007]

In order to achieve this object, a millimeter wave information reading system according to the present invention uses a millimeter wave as an information transmission medium and inputs a millimeter wave to each of a large number of antenna elements. By controlling the phase of, the focal point where the millimeter waves radiated from the multiple antenna elements are concentrated is scanned in a predetermined space, and the millimeter wave reflected from the irradiation position of the focal point is transmitted to the multiple antenna elements. And a host having a phased array transmission / reception antenna for detecting the temporal change thereof, and information that causes a specific temporal change in the millimeter wave reflected from the irradiation position by the scanning of the focal point. Alternatively, a card formed of a material that scatters and reflects millimeter waves and a material that does not reflect the millimeter waves is provided on the inner surface.

[0008]

The host-side phased array transmission / reception antenna determines the radiated power in transmission and the detection sensitivity in reception.
While concentrating as the same focus in the reading target space,
The space is scanned at high speed by electrically controlling the direction and distance of the focal point. The focal point of the millimeter-wave power radiated from the phased array transmitting / receiving antenna is incident on a card on which specific information is formed using a material that scatters and reflects the millimeter wave and a material that does not reflect the millimeter wave.

Here, when the focal point passes through a material that scatters and reflects the millimeter wave, the incident millimeter wave is scattered and reflected, and a part of the power is received by the phased array transmitting / receiving antenna. Also, when the focal point passes through a material that does not reflect the millimeter wave, the incident millimeter wave is not reflected, so that the phased array transmitting / receiving antenna does not receive the millimeter wave power. When the focus passes over the card in this way,
In the phased array transmission / reception antenna, information written on the card is received as a temporal intensity change of the millimeter wave.

[0010]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present millimeter wave information reading system, FIG. 2 is a block diagram on the host side, FIG. 3 (a) is a card outline drawing, and FIG.

In FIG. 1, reference numeral 11 denotes a host having a phased array transmission / reception antenna 12. The phased array transmission / reception antenna 12 focuses the radiated power in transmission and the density of detection sensitivity in reception on the same focal point 13. The space 14 to be read at the focal point 13
A millimeter wave beam 16 that scans the inside at high speed is irradiated. Fifteen
Is a card, on which a barcode 17 in which information is recorded using a material that scatters and reflects the millimeter wave and a material that does not reflect the millimeter wave is formed. Reference numeral 18 denotes an external signal processor that receives an information signal read from the host 11.

FIG. 2 specifically shows a block diagram on the host side. The host is a phased array transmission / reception antenna 2 including a control device 21, a power distribution / synthesizer 24, a phase variable device 25, and an antenna array 27 including a group of patch antennas 26.
8, a millimeter-wave oscillator 22, a transmission / reception separator 23, and a millimeter-wave detector 29.

The millimeter wave oscillator 2 is controlled by the control device 21.
The millimeter wave output from 2 is input to the power distribution / combiner 24 through the transmission / reception separator 23. The power divider / combiner 24 distributes the millimeter wave into an appropriate power ratio under the control of the control device 21 and sends it to the phase variable device 25. The phase variable unit 25 sends each millimeter wave distributed under the control of the control device 21 to the antenna array 27 with an appropriate phase delay, and the antenna array 27 transmits the input millimeter wave to each patch antenna 2.
The light is radiated through 6 to the space to be read. Here, the power distribution combiner 24 and the phase changer 25 use a bidirectional reversible device.

Conversely, the millimeter waves reflected from the space to be read pass through the patch antenna 26 and pass through the antenna array 2.
7 to the phase variable unit 25, receives the same phase delay as the transmission, and sends it to the power distribution / combiner 24. The power divider / combiner 24 combines the received powers of the received millimeter waves and sends the combined power to the transmission / reception separator 23. The received millimeter wave output from the transmission / reception separator 23 is detected by a millimeter wave detector 29 controlled by the control device 21 and output to an external signal processor.

Next, FIG. 3 shows a structural view and an external view of the card of this embodiment. The outer shape of the card can be made as thick as a business card. As shown in FIG. 3A, the structure of the card 31 is a bar code 35 including a scattering reflector 33 that scatters and reflects millimeter waves and a non-reflective member 34 that does not reflect millimeter waves, and a paper 32 that sandwiches the bar code 35. , And printed characters 36 written on paper 32. The scattering / reflecting material 33 has a metal coating having fine irregularities on its surface, and the non-reflective material 34 has a metal coating or the like having a large loss with respect to millimeter waves, or has a relative permittivity of transmitting millimeter waves. Paper, paint, and the like can be used. As shown in FIG.
5 has a structure that cannot be seen from the surface of the card 31.

The operation of the millimeter wave information reading system configured as described above will be described with reference to FIG. 1 again. Now, the card 15 is in the reading target space 14, and the focal point 13 at which the host 11 scans the entire reading target space 14 at high speed is the bar code 17 of the card 15.
When passing across the line that constitutes
When 3 is on a line written with a material that scatters and reflects millimeter waves, the incident millimeter waves are scattered and reflected, and a part of the power is received by the phased array transmitting / receiving antenna 12. When the focal point 13 is on a line written with a material that does not reflect the millimeter wave, the incident millimeter wave is not reflected and the phased array transmission / reception antenna 12 does not receive the millimeter wave power.

When the focal point 13 passes over the bar code 17 in the card 15, the information written in the bar code 17 is received by the phased array transmitting / receiving antenna 12 as a temporal intensity change of the millimeter wave. You. The received information is sent from the host 11 to the external signal processor 18. When the millimeter-wave information reading system is used for, for example, entry / exit management, the external signal processor 18 performs necessary processing such as collation of information of a received signal with information registered in advance. .

As described above, in the present embodiment, a system for reading information using the phased array transmitting / receiving antenna 12 for concentrating the radiated power and the detection sensitivity of the millimeter wave on the host 11 at the same focal point is configured. Can be made very small. For this reason, even if the antenna is miniaturized, the millimeter-wave radiation power from the host can be small, and a system with high sensitivity and a long reading distance can be realized. Further, by electrically controlling the scanning of the focal point, the inside of the reading target space 14 can be scanned at high speed in a short time, and a system with high reading accuracy can be realized.

Since the card may be a card in which information is written using a metal paint or paper, it can be realized very thinly and at a low price, and since no battery is used, the life does not matter. Also, the material forming the barcode is sandwiched between papers, and characters and the like are written on the paper to form a business card as shown in FIG. 3 (b). You can make cards that are difficult to be played. Since the millimeter wave is not easily affected by a thin nylon material or a high polymer material, it is possible to insert a card into a regular insert.

Further, since it is also possible to apply a glue to a card to form a seal and affix it to a wrapping paper or a packing box, or to attach a cloth to a card and attach it to a garment so that it can be applied to clothes. When a barcode is formed on the surface of the card, the same color can be used for the scattered reflection material and the non-reflection material to make it impossible to read visually, and it is possible to make a card that is difficult to imitate. .

[0021]

According to the present invention, an information reading system having the following excellent effects can be realized. ○ By using a phased array transmit / receive antenna that concentrates the radiated power and detection sensitivity of millimeter waves at the same focal point, the millimeter wave transmission loss of the system can be extremely reduced, and the millimeter wave radiated power from the host is small. A system with good sensitivity and a long reading distance can be realized. -The system can be configured with low-priced cards that are thin and do not have a long life, and can be applied not only to room access control but also to various fields.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a millimeter wave information reading system according to an embodiment of the present invention.

FIG. 2 is a block diagram on the host side of the millimeter wave information reading system.

FIG. 3A is a structural view of a card of the millimeter-wave information reading system. FIG. 3B is an external view of a card of the millimeter-wave information reading system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Host 12 Phased array transmission / reception antenna 13 Focus 14 Space to be read 15 Card 16 Millimeter wave beam 17 Barcode 18 External signal processor 21 Controller 22 Millimeter wave oscillator 23 Transmitter / receiver separator 24 Power distribution combiner 25 Phase variable device 26 Patch Antenna 27 Antenna Array 28 Phased Array Transmit / Receive Antenna 29 Millimeter Wave Detector 31 Card 32 Paper 33 Scattering Reflector 34 Non-Reflective Material 35 Barcode 36 Printed Character

Claims (1)

(57) [Claims] The present invention controls a phase of a millimeter wave input to each of a large number of antenna elements, thereby scanning a focal point where millimeter waves radiated from the large number of antenna elements concentrate in a predetermined space, and Millimeter waves reflected from the irradiation position of the focus are received by the multiple antenna elements,
A host equipped with a phased array transmission / reception antenna for detecting the temporal change, and information that causes a specific temporal change in the millimeter wave reflected from the irradiation position by the scanning of the focal point, on its surface or inner surface. A millimeter wave information reading system including a card formed of a material that scatters and reflects a millimeter wave and a material that does not reflect the millimeter wave.