JP2005198047A - Antenna for information processor, and information processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an efficient antenna while avoiding difficulties in condenser regulation. <P>SOLUTION: A secondary coil is arranged in each of a plurality of divided areas into which an area where the antenna is to be arranged has been divided. That is, a plurality of secondary coils of smaller area are arranged. The primary coil is common to the plurality of secondary coils. Thus, it is possible to avoid the difficulties in condenser regulation and, at the same time, to use the limited area for forming the antenna effectively (an area occupied by a conductor becomes smaller than the whole area of the antenna) and to improve the efficiency of the antenna. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an information processing apparatus that transmits and receives data to and from an information recording medium in a contactless manner and an antenna unit thereof.

  At present, the introduction of a non-contact carrier system capable of non-contact communication with a non-contact information recording medium incorporating an IC is becoming popular. For example, a traffic gate entrance / exit device such as an automatic ticket gate at a station using an “IC card” with a built-in IC in a card, an entrance / exit room management device, and a tag “IC tag” with a built-in IC attached to the product for product management 2. Description of the Related Art Non-contact recording media of various sizes and non-contact carrier systems using the same are known, such as a physical distribution management device, an entrance / exit room management device using an “IC wristband” with a built-in IC in a wristwatch, and the like.

  An information processing device such as an IC card reader / writer device that performs communication with the non-contact type recording medium as described above usually employs an antenna having a loop coil. As a loop coil constituting this antenna, for example, as shown in FIG. 12, an antenna 100 in which a primary coil 101 and a secondary coil 102 coupled to the primary coil 101 by mutual induction are transformer-coupled is generally used. Is done.

  Further, as shown in FIG. 13, a plurality of pairs of primary coils and secondary coils are arranged on the same plane (in FIG. 13, pairs of primary coil 111 and secondary coil 112, and primary coils 113 and 2). An antenna 110 having a configuration in which primary coils 111 and 113 are connected in parallel has also been proposed (FIGS. 2, 5, 10, and 11 of Patent Document 1). And “0148”). The two pairs are, for example, four rectangles obtained by dividing a predetermined rectangle (such as a rectangle which is a cross section of a conventional loop coil) into two in the vertical and horizontal directions (see FIG. 2 of Patent Document 1). Two of the four coils whose cross-section is shown are shown.

Here, in an information processing apparatus that performs communication with a non-contact type recording medium, it is desired to extend the communication distance. In order to extend the communication distance, it is necessary to increase the magnetic field generated by the antenna. The generated magnetic field is proportional to the number of turns of the antenna when the current flowing through the antenna is constant. However, in the configuration of FIG. 12, when the number of turns is increased, the set value of the capacitor 103 becomes smaller and adjustment becomes difficult. On the other hand, in the configuration of FIG. 13, as described above, a plurality of pairs of primary and secondary coils having a smaller area (1/2, 1/4, etc.) than the configuration of FIG. 12 are formed on the same plane. By connecting the primary coils in parallel, the antenna load as seen from the signal processing circuit is lightened, so the current increases (increases the magnetic flux) and the inductance of the secondary coil decreases. Magnetic flux can be increased without reducing it.
JP-A-8-194785 (FIGS. 2, 5, 10, and 11)

  However, the conventional configuration has a problem that the efficiency of the antenna is poor. In the conventional configuration, the primary and secondary coils are patterned in a predetermined width (for example, 1 mm) on the same plane on the printed circuit board. The loop coil is made of a conductor (conductive member) such as copper, but as is well known, the conductor has a resistance, and a resistance loss occurs with respect to the current flowing through the loop coil.

  This resistance loss can be reduced by increasing the width of the pattern. However, increasing the width increases the proportion of the coil itself in the area inside the coil, which degrades the efficiency of the antenna.

  Thus, if the width of the pattern is widened in order to suppress the resistance loss, there arises a problem that the antenna efficiency is lowered in the antenna having the primary coil and the secondary coil. This situation becomes more prominent when a plurality of loop coils having a small area are arranged as shown in FIG. However, in the configuration of FIG. 13, it is possible to avoid the difficulty of adjusting the capacitor. Therefore, it is desirable that the antenna efficiency be improved compared to the configuration of FIG. 13 while maintaining this feature.

  In addition, it is known that the transformer coupling between the primary coil and the secondary coil should have a smaller distance between patterns (conductors). Good transformer coupling means good antenna efficiency. However, the distance between the conductors increases with increasing pattern width. An example is shown in FIG. FIG. 14A shows a case where the pattern width is narrow, and FIG. 14B shows a case where the pattern width is wide. As shown in the drawing, even if the distance between the outer loop of the primary coil and the inner loop of the secondary coil does not change, the distances a and b between the outer loop of the primary coil and the outer loop of the secondary coil are: It grows as the width of the pattern increases. As described above, when the width of the pattern is widened to reduce the resistance loss, the distance between the conductors is increased, which is one of the causes of the deterioration of the antenna efficiency.

  As a method for demodulating the signal, a method of demodulating the primary coil voltage or the secondary coil voltage (capacitor voltage) is used in FIG. However, the magnitude of the demodulated signal voltage may vary depending on the type of non-contact type recording medium. As a corresponding method, for example, if the demodulation circuit is adjusted for a recording medium with the smallest signal voltage, an attenuator is attached before the detection circuit or the amplification circuit is amplified for a medium with a large signal voltage. However, this causes problems such as increased loss and circuit complexity.

  In the configuration of FIG. 13, a demodulation method is employed in which the waveforms of the voltages of the two secondary coils are detected and the detected waveforms are added and amplified. In this case, detection circuits are required as many as the number of coils, which causes problems that the circuit becomes complicated and costs increase.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an efficient antenna while avoiding the difficulty of capacitor adjustment, or to provide a demodulating circuit in which the magnitude of a signal voltage to be demodulated differs depending on the type of non-contact recording medium It is an object to provide an information processing apparatus capable of appropriate demodulation while avoiding complication and cost increase.

  An antenna of an information processing apparatus according to the present invention is an antenna used in an information processing apparatus that transmits and receives signals without contact with an information recording medium, and the antenna includes a primary coil and a secondary coil coupled to the primary coil by mutual induction. The secondary coil is configured as a plurality of secondary coils arranged in each divided region obtained by dividing the region where the antenna is to be arranged, and the primary coil is connected to the plurality of secondary coils. Arrange as common.

  In the above configuration, when the primary coil is composed of, for example, two secondary coils, one common primary coil is disposed in the two secondary coils. By adopting such a configuration, it is possible to effectively use the area of a limited region for forming the antenna while avoiding the difficulty of adjusting the capacitor (the primary coil conductor is smaller than the entire antenna area). The ratio of the occupancy is smaller than that in the configuration of FIG.

  In the antenna, for example, the primary coil and the plurality of secondary coils are patterned on the same plane of a printed circuit board, and the primary coil forms a crossover at a position intersecting with the plurality of secondary coils. Consists of.

Alternatively, the antenna may be configured, for example, by arranging the primary coil and the plurality of secondary coils on different planes.
Alternatively, the antenna may be configured, for example, by arranging the plurality of secondary coils such that each of the plurality of loop coils constituting the secondary coil is spaced apart in the axial direction. .

  With this configuration, the area of the limited area for forming the antenna can be used more effectively, and the distance between the conductors can be increased even if the pattern width is increased to reduce resistance loss. Since it depends on the distance in the axial direction, it does not have to be large.

Further, for example, the primary coil may be arranged such that a plurality of loop coils constituting the primary coil are spaced apart in the axial direction.
An information processing apparatus according to the present invention is an information processing apparatus that transmits and receives signals without contact with an information recording medium using each of the antennas described above, a demodulation circuit that detects and demodulates a voltage of a secondary coil, and the plural And selecting means for selectively inputting, to the demodulating circuit, an arbitrary voltage or a combined voltage of a plurality of voltages from the voltages generated in the secondary coil.

  The selection unit is configured to selectively input, for example, an arbitrary voltage or a composite voltage of a plurality of voltages from the voltages of the loop units constituting the secondary coils to the demodulation circuit. .

  In the information processing apparatus, when the magnitude of the signal voltage varies depending on the type of the non-contact type recording medium, for example, one voltage for a recording medium with a small signal voltage, and a recording medium with a large signal voltage. Selects a composite voltage and inputs it to the demodulation circuit.

  According to the present invention, it is possible to provide an efficient antenna with low power consumption while avoiding difficulty in adjusting a capacitor. Further, according to the information processing apparatus of the present invention, the demodulation voltage can be adjusted according to the magnitude of the signal voltage of the non-contact recording medium without complicating the circuit. Miniaturization is possible.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic configuration diagram of an information processing apparatus 10 that is a reader / writer apparatus or the like of a non-contact information recording medium 20 including an antenna according to the present embodiment.

  The information processing apparatus 10 is constructed in various places such as a ticket gate of a station, entrance / exit management, logistics management, etc., and a contactless information recording medium 20 such as an IC card or an IC tag by an antenna 16. Communicate in a non-contact manner, and read / write arbitrary data.

  The antenna 16 is created by patterning a loop coil on the printed circuit board 17. The first feature of this example is the configuration of the antenna 16, and the specific configuration is shown in FIGS. 2 to 5 and will be described later.

  The information processing apparatus 10 includes a signal processing circuit 11 and a computer 18. The computer 18 is a CPU, a memory, etc. (not shown), for example. The signal processing circuit 11 includes a carrier signal generator 12, an amplifier 13, a demodulation circuit 14, and a digital signal processing unit 15. The demodulation circuit 14 includes a detection circuit 14a and an amplification circuit 14b. The signal processing circuit 11 performs non-contact communication with the non-contact information recording medium 20 using the antenna 16. The computer 18 receives a signal from the signal processing circuit 11 and performs processing, or transmits data to the signal processing circuit 11 to transmit data to the non-contact information recording medium 20 via the antenna 16.

  The carrier signal generator 12 generates a carrier signal having a predetermined frequency. The digital signal processing unit 15 changes the amplification factor of the amplifier 13 according to the information to be transmitted. As a result, the carrier signal level changes (amplitude modulation). This amplitude-modulated wave is radiated from the antenna 16 as an electromagnetic wave. Thereafter, the signal processing circuit 11 radiates an unmodulated wave as an electromagnetic wave while keeping the amplification factor of the amplifier 13 constant for a certain period. On the non-contact information recording medium 20 side, the digital signal processing unit 23 performs on / off control of the switch 22 according to the data to be returned. As a result, the resonance frequency (impedance) of the resonance circuit composed of the loop coil 21 and the capacitor 24 changes, and the carrier signal of the signal processing circuit 11 changes. The detection circuit 14a of the demodulation circuit 14 detects this carrier signal, and the amplification circuit 14b amplifies the signal after the detection. The digital signal processing unit 15 identifies the variation of the carrier signal from the amplified signal, recognizes the data transmitted from the recording medium 20 side, and transfers this to the computer 18.

  The signal processing circuit 11 may have a conventional general configuration. However, the configuration relating to the input to the demodulation circuit 14 is the configuration shown in FIGS. 7 and 9 to be described later, and the magnitude of the signal voltage to be demodulated differs depending on the type of the non-contact information recording medium 20 However, problems such as complication of the demodulation circuit 14 may be avoided. This is the second feature of this example.

  In the configuration of the recording medium 20, the diode 25 is a rectifying / detecting diode, and the capacitor 26 is a smoothing capacitor. In FIG. 1, the antenna 16 is not specifically distinguished from a primary coil and a secondary coil, but actually comprises a primary coil and a secondary coil as will be described later. The carrier signal generated by 12 is applied to the primary coil, and the detection circuit 14a detects the voltage fluctuation of the secondary coil.

2 to 5 show the configuration of the antenna 16 according to the present embodiment, respectively.
FIG. 2 shows an antenna 16a according to the first embodiment, FIG. 3 shows an antenna 16b according to the second embodiment, FIG. 4 shows an antenna 16c according to the third embodiment, and FIG. 5 shows a specific example of the antenna 16d according to the fourth embodiment.

  A common feature of these antennas 16a to 16d is that a secondary coil is arranged in each divided area obtained by dividing the area where the antenna is arranged in order to avoid difficulty in adjusting the capacitor. That is, the secondary coil is provided with a plurality of secondary coils having a smaller area than that in FIG. On the other hand, the primary coil is one primary coil common to the plurality of secondary coils.

  With the above configuration, the area of a limited region for forming the antenna can be used effectively (the ratio of the conductor of the primary coil to the total area of the antenna is smaller than the configuration of FIG. ) And antenna efficiency is improved. By configuring the secondary coil as a plurality of secondary coils having a small area, the number of turns of the coil is larger than that of one coil having the same cross-sectional area as the area occupied by all of the plurality of secondary coils. Alternatively, since the current flowing in the outer periphery of the coil is large, the strength of the magnetic field can be improved. Therefore, the magnetic flux can be increased without reducing the set value of the capacitor, and the difficulty of adjusting the capacitor can be avoided. The plurality of secondary coils are preferably formed in the same or substantially the same shape (and the number of turns is also the same). In this way, currents of the same phase flow through a plurality of secondary coils having the same characteristics.

First, a configuration example of the antenna 16a according to the first embodiment illustrated in FIG. 2 will be described.
The antenna 16a shown in FIG. 2 includes primary and secondary coils on the same plane of the printed circuit board 17, for example, on the surface of the printed circuit board 17. Here, one of the two surfaces of the printed circuit board 17 is referred to as the front surface, and the other as the back surface.

  The primary coil 31 is connected to the signal processing circuit 11. The secondary coil includes two coils 32 and 33 that are electromagnetically coupled to the primary coil 31. This configuration can be said to be a configuration in which the conventional secondary coil 102 of FIG. 12 is divided into two (the area that the area obtained by adding both the secondary coils 32 and 33 is substantially the same as the area of the secondary coil 102. It is in).

  The primary coil 31 is disposed inside the secondary coil. Therefore, the outer periphery of the primary coil is smaller than the inner periphery of the secondary coil (which means a combination of the two coils 32 and 33 here). In this configuration, as it is, the primary coil 31 and the secondary coils 32 and 33 come into contact with each other. Therefore, as shown in FIG. 2, at the position where the primary coil 31 and the secondary coils 32 and 33 intersect, A part of the primary coil 31 is formed on the back surface of the printed circuit board 17 (dotted line portion of the primary coil in the figure; primary coil connecting wire 31a).

  With such a configuration, each loop constituting the secondary coils 32 and 33 has a smaller area (about half) than the secondary coil 102 having the conventional configuration shown in FIG. The number of turns increases, the inductance decreases, and the capacitor capacity can be increased. Furthermore, as compared with the configuration of FIG. 13, the primary coil 31 is configured as one coil common to the two secondary coils 32 and 33, so that the limitation for forming the antenna as described above. The area of the selected region can be used effectively (the ratio of the conductor to the entire antenna area is reduced), and the antenna efficiency is improved. That is, it is possible to provide an efficient antenna while avoiding the difficulty of capacitor adjustment.

  In the illustrated example, the example in which the secondary coil is arranged in each divided region obtained by dividing the region in which the antenna is arranged into two, that is, an example in which the number of secondary coils is two, is shown as an example. For example, the area where the antenna is arranged may be divided into four and four secondary coils may be arranged. In this case, the number of primary coils may be one or two.

Next, a configuration example of the antenna 16b according to the second embodiment illustrated in FIG. 3 will be described.
In the configuration shown in FIG. 3, the primary coil 41 is formed by patterning a loop coil on the back surface of the printed circuit board 17, and the secondary coils 42 and 43 are formed on the surface of the printed circuit board 17. Therefore, although omitted in FIG. 3, the printed circuit board 17 exists between the primary coil 41 and the secondary coils 42 and 43. However, this is only an example, and the positional relationship between the primary coil 41 and the secondary coils 42 and 43 is not shown in FIG. In the axial direction that is the crossing direction of the planes including the surface.

  The configuration shown in FIG. 3 is characterized in that one primary coil 41 is provided common to the two secondary coils 42 and 43 as in the configuration of FIG. 2, but the primary coil 41 is replaced with the secondary coils 42 and 43. 2 is different from FIG. 2 in that it is formed on a different surface.

Next, a configuration example of the antenna 16c according to the third embodiment illustrated in FIG. 4 will be described.
In the configuration shown in FIG. 4, the primary coil 41 is the same as the primary coil shown in FIG.

  On the other hand, with respect to the secondary coil, in the conventional and the configurations of FIGS. 2 and 3 above, a plurality of loops constituting each secondary coil are arranged on the same plane. It arrange | positions so that it may arrange | position on a different plane. That is, as in the example shown in FIG. 4, the two loops 51 a and 51 b constituting the secondary coil 51 are arranged on different planes (with an interval on the axial direction that is the intersecting direction of the plane including the loop coil). These two loops 51a and 51b are connected in series. The same applies to the secondary coil 52. The two loops 51a and 51b are arranged on different planes and connected in series. As a method of arranging the loops at intervals in the axial direction in this way, for example, there is a method of forming a loop coil pattern on each laminated surface of the laminated printed board. However, the present invention is not limited to this. For example, patterns may be formed on a single-phase printed circuit board, and they may be separated and supported by a spacer or the like.

  In such an arrangement, unlike the case where the loop coil pattern is formed on the same plane as shown in FIG. The decrease in the antenna area due to this is slightly suppressed.

  Furthermore, in the case of the configuration of FIG. 4, even if the width of the pattern is increased, the distance between conductors can be reduced as compared with the conventional case. That is, in the figure, for the sake of clarity, the axial interval of the loop coil is shown to be large, but in practice, for example, the distance between the laminated surfaces of the laminated printed circuit board is smaller than the width of the pattern. . In particular, in this method, the width of the pattern is widened in order to reduce the resistance loss. As described above, the antenna efficiency is improved when the distance between the conductors is small. Therefore, the antenna efficiency is further improved as compared with the configuration of FIG. 3 (same as in FIG. 2) as shown in the experimental results shown in FIG. ing. The same applies to the configuration of FIG.

Next, a configuration example of the antenna 16d according to the fourth embodiment illustrated in FIG. 5 will be described.
In the configuration shown in FIG. 5, the secondary coils 51 and 52 are the same as the secondary coil shown in FIG.

  Further, in the configuration shown in FIG. 5, the two loops 61 a and 61 b constituting the primary coil 61 are arranged on different planes (loops) as in the case of the secondary coils 51 and 52. The two loops 61a and 61b are connected in series in the axial direction that is the crossing direction of the plane including the coil.

  In FIGS. 4 and 5, the loop coil is arranged at one place separated in the axial direction. However, the present invention is not limited to this. For example, in the case of a loop coil with 6 turns as an example, the configuration in which the loop coil is arranged at one place described above has an arrangement of 6 layers as shown in FIG. 6A. For example, as shown in FIG. It may be arranged in three layers by arranging in two places.

  In the configuration examples shown in FIGS. 1 to 5 described above, the shape of the loop coil is basically the same (different between the different types of primary coil and secondary coil). It does not have to be substantially the same. That is, the shape may be varied within a range in which target characteristics can be obtained. In the above description, the number of secondary coils is two, but the number is not limited to this. Further, although the number of loops of the primary and secondary coils is two, it is not limited to this. The secondary coils described above each have capacitors C1 and C2 to form a resonance circuit, and the resonance frequency of the resonance circuit is the same as or substantially the same as the frequency of the carrier generated by the carrier signal generator 12. It is good. Further, the number of turns of the secondary coil may be larger than the number of turns of the primary coil (this can improve the strength of the magnetic field generated from the secondary coil). The plurality of secondary coils may be formed in the same or substantially the same shape.

  FIG. 7 shows the actual magnetic flux φ generated by the antenna, the current I of the primary coil of the antenna, and the ratio “φ / I” for the antenna configuration of the present embodiment and the conventional antenna configuration of FIG. The comparison result based on the actual measurement data by the experiment is shown.

  In FIG. 7, the actual measurement data of the generated magnetic flux φ of the antenna, the current I of the primary coil of the antenna, and the ratio “φ / I” for the antenna configuration of FIG. The comparison result with the actual measurement data of the antenna configuration is shown.

  As shown in the figure, in the case of the configuration of FIG. 3, the magnetic flux is slightly smaller than in the conventional case, but since the antenna input current is further reduced, the ratio (efficiency) φ / I is improved by 20%. Further, according to the configuration of FIG. 4, the magnetic flux is the same as the conventional one, but the current is further reduced, so that the efficiency is improved by 47%.

FIG. 8 is a diagram for explaining a detection / demodulation method in the information processing apparatus 10 according to the present example.
Conventionally, detection / demodulation methods include a method of detecting the voltage on the primary coil side and a method of detecting the voltage on the secondary coil side. In this method, a method of detecting the voltage on the secondary coil side is used. take. The configuration of the secondary coil is based on the configuration shown in FIG. 4 or 5, that is, the configuration in which each loop is arranged on a different plane. Thus, FIG. 8 shows a secondary coil 51 composed of loops 51a and 51b and a secondary coil 52 composed of loops 52a and 52b as secondary coils. Further, FIG. 8 shows an example in which the detection / demodulation method of the present method is applied only to the secondary coil 52, but it may be applied to the secondary coil 51 or to both.

  The characteristic of the detection / demodulation method of this method is the voltage selection unit 71 shown in FIG. That is, normally, when detecting the voltage of the secondary coil, the voltage at the connection point between the secondary coil and the capacitor is detected. That is, the voltage V2 between the points A and C in FIG. 8 is detected. On the other hand, in this method, the wiring is drawn from the point B between the loops 52a and 52b, and the voltage V1 between the points A and B can be detected. Then, the voltage selection unit 71 selects either the voltage V1 between point A and point B or the voltage V2 between point A and point C, and this is used as the input of the demodulation circuit 14.

  With the above configuration, for example, the voltage selection unit 71 is switched to the point C side for the recording medium 20 having a small signal voltage, and the voltage V2 is input to the demodulation circuit 14. Thereafter, when the recording medium 20 having a large signal voltage is used for some reason, the voltage selection unit 71 is switched to the B point side and the voltage V1 is input to the demodulation circuit 14. As a result, it is not necessary to adjust the demodulator circuit 14 one by one, and it is not necessary to change the attenuator in front of the detector circuit or to reduce the amplification degree of the amplifier circuit. The problem can be solved. Thus, the demodulation voltage can be adjusted according to the magnitude of the signal voltage of the non-contact recording medium without complicating the circuit, so that the demodulation accuracy can be improved and the apparatus can be downsized.

  Such switching is performed because the magnitude of a return signal from the medium changes according to the type (card, tag, wristband, etc.) and characteristics (card frequency) of the target medium (recording medium 20). This is very useful when it is desired that one information processing apparatus 10 can handle various types of media.

The voltage selection unit 71 may be realized simply by a changeover switch, but may be realized by the configuration shown in FIG.
In the example shown in FIG. 9, on the printed board on which the antenna (secondary coil) is patterned, the conductor pattern 72 connected to the point C and the conductor pattern 72 connected to the point B in FIG. 14 and the chip-type short-circuit resistors 73c and 73b (here, the chip-type short-circuit resistor 73c is a point C and the chip-type short-circuit resistor 73b is a connection resistor to the point B). The switching is realized by changing the chip-type short-circuit resistors 73b and 73c. That is, one is “no connection” and the other is connected to a chip of “zero resistance”. For example, when it is desired to use the voltage V1 between point A and point B, the chip-type short-circuit resistor 73b is a “zero resistance” chip, and the chip-type short-circuit resistor 73c is not connected.

  However, simply selecting whether or not the “zero resistance” chip is attached in this way is not much different from the case of using the changeover switch. The reason why the chip-type short-circuit resistor is used is not limited to an example of using a “zero resistance” chip, but also a case where a chip having an arbitrary resistance value is considered.

  For example, taking the chip-type short-circuit resistor 73c as an example, making this a chip having an arbitrary resistance value means the circuit shown in FIG. That is, selecting the resistance value according to the signal from the medium can be regarded as substantially equivalent to connecting a variable resistor as shown in FIG. Therefore, since the voltage to the demodulator circuit 14 can be changed by changing the resistance value, it is not necessary to change the circuit constant of the demodulator circuit 14 itself, and more detailed setting is possible (see FIG. If a changeover switch is used in step 8, only two-stage switching is possible).

  Further, the demodulation method according to the present method is not limited to the configuration shown in FIG. In FIG. 11, by short-circuiting the point C and the point D shown in the figure, the voltage selection unit 74 selects one of the voltages V1 to V4 shown in the figure, and the demodulation circuit 145 demodulates the voltage. In this case, if a change-over switch is used, it is possible to perform four-stage switching as compared to the two-stage switching in FIG. 8, and the voltage demodulated by the demodulation circuit 14 can be set more finely. . Of course, a resistor may be used as shown in FIG. The voltage selection unit 74 is substantially the same as the voltage selection unit 71, and there is only a difference from the two-stage selection or the four-stage selection. In addition, if the configuration of FIG. 11 is used, it can be applied not only to the configurations of FIGS. 4 and 5, but also to the configurations of FIGS. That is, in the case of the configuration of FIG. 2 and FIG. 3, the connection to the point B and the connection to the point E shown in FIG.

It is a schematic block diagram of the information processing apparatus which is a reader / writer apparatus etc. of a non-contact-type information recording medium. It is a figure which shows the structural example of the antenna by Example 1. FIG. FIG. 6 is a diagram illustrating a configuration example of an antenna according to a second embodiment. 6 is a diagram illustrating a configuration example of an antenna according to Embodiment 3. FIG. It is a figure which shows the structural example of the antenna by Example 4. FIG. (A), (b) is a figure for demonstrating a modification. It is a figure which shows the difference of the antenna efficiency etc. with the conventional antenna based on an experimental result. It is FIG. (1) for demonstrating the detection and demodulation method by this example. It is a figure which shows the specific example of the voltage selection part of FIG. It is a figure for demonstrating the advantage using the structure of FIG. It is FIG. (2) for demonstrating the detection and demodulation method by this example. It is FIG. (1) which shows the example of a conventional antenna structure. It is FIG. (2) which shows the example of a conventional antenna structure. It is a figure for demonstrating the problem of the conventional antenna.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Information processing apparatus 11 Signal processing circuit 12 Carrier signal generator 13 Amplifier 14 Demodulation circuit 14a Detection circuit 14b Amplification circuit 15 Digital signal processing part 16 Antenna 17 Printed circuit board 18 Computer 20 Contact non-type information recording medium 21 Loop coil 22 Switch 23 Digital Signal Processing Unit 24 Capacitor 25 Diode 26 Capacitor 31 Primary Coil 31a Primary Coil Crossover 32 Secondary Coil 33 Secondary Coil 41 Primary Coil 42 Secondary Coil 43 Secondary Coil 51 Secondary Coil 51a Loop 51b Loop 52 Secondary Coil 52a Loop 52b Loop 61 Primary coil 71 Voltage selection unit 72 Conductor pattern 73b Chip type short circuit resistance 73c Chip type short circuit resistance 74 Voltage selection unit

Claims (9)

In an antenna used in an information processing apparatus that transmits and receives signals without contact with an information recording medium,
The antenna includes a primary coil and a secondary coil coupled to the primary coil by mutual induction.
The secondary coil is configured as a plurality of secondary coils respectively arranged in each divided region obtained by dividing the region in which the antenna is to be arranged.
The antenna for an information processing apparatus, wherein the primary coil is arranged as a common coil for the plurality of secondary coils.   The primary coil and the plurality of secondary coils are patterned on the same plane of a printed circuit board, and the primary coil forms a crossover at a position intersecting with the plurality of secondary coils. Item 10. An information processing apparatus antenna according to Item 1.   The antenna of an information processing apparatus according to claim 1, wherein the primary coil and the plurality of secondary coils are arranged on different planes.   The antenna of an information processing apparatus according to claim 3, wherein each of the plurality of secondary coils is arranged such that a plurality of loop coils constituting the secondary coil are spaced apart in the axial direction. .   5. The antenna of an information processing apparatus according to claim 4, wherein the primary coil is arranged such that a plurality of loop coils constituting the primary coil are spaced apart in the axial direction.   The plurality of loop coils constituting the secondary coil or the primary coil are arranged so as to be spaced apart in the axial direction by patterning the loop coils for each laminated surface of the laminated printed board. The antenna of the information processing apparatus according to claim 4 or 5, wherein the antenna is provided. Each of the plurality of secondary coils includes a capacitor to form a resonance circuit,
The number of turns of the plurality of secondary coils is larger than the number of turns of the primary coil,
The antenna of the information processing apparatus according to claim 1, wherein the plurality of secondary coils are formed in the same or substantially the same shape as each other. An information processing apparatus using the antenna according to claim 1,
A demodulation circuit for detecting and demodulating the voltage of the secondary coil;
A selection means for selectively inputting any one voltage or a combined voltage of a plurality of voltages from the voltages generated in the plurality of secondary coils to the demodulation circuit;
An information processing apparatus comprising: The selection means selectively inputs an arbitrary voltage or a composite voltage of a plurality of voltages from the voltages of each loop unit constituting the secondary coils to the demodulation circuit. Item 9. The information processing apparatus according to Item 8.

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