CARD DETECTION DEVICE HAVING A MAGNETIC FIELD MONITOR, SYSTEM INCLUDING THE DEVICE, AND METHOD OF OPERATING THE DEVICE

• US 20150270876A1
• Filed: 03/17/2015
• Published: 09/24/2015
• Est. Priority Date: 03/18/2014
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Chol S.U. Yoon, Jun H.O. Kim
• Inventors: YOON, CHOL SU, KIM, JUN HO, CHOI, HYUK SANG
• Granted Patent: US 9,991,937 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04B 5/24 Inductive coupling
• CPC Class Codes: H04B 5/26 using coils
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04B 5/77 for interrogation

Abstract

A detection device is provided. The detection device includes a transmitter and a detector. The transmitter supplies an induced current to an antenna and to adjust a strength of an induced voltage generated in the antenna by adjusting the induced current. The detector monitors the strength of the induced voltage of the antenna and generates a control signal for controlling the induced current to the antenna based on the monitored strength of the induced voltage of the antenna.

Claims

1. A detection device, comprising:

a transmitter supplying an induced current to an antenna and adjusting a strength of an induced voltage generated in the antenna by adjusting the induced current; and

a detector monitoring the strength of the induced voltage of the antenna and generating a control signal for controlling the induced current to the antenna based on the monitored strength of the induced voltage of the antenna.

2. The detection device of claim 1, wherein the card detector comprises:

a rectifier rectifying the induced voltage and generating a rectified voltage;

an attenuator attenuating the rectified voltage and generating an attenuated voltage; and

a detection block comparing at least one voltage generated based on the attenuated voltage with at least one reference voltage and generating the control signal based on the comparison result.

3. The detection device of claim 2, wherein the detection block comprises:

a first comparator comparing a first voltage obtained by dividing the attenuated voltage with a first reference voltage;

a second comparator comparing a second voltage obtained by dividing the attenuated voltage with a second reference voltage; and

a controller generating the current control signal based on output signals of the first and second comparators.

4. The detection device of claim 1, wherein the card detector comprises:

a rectifier rectifying the induced voltage and generating a rectified voltage;

an attenuator attenuating the rectified voltage and generating an attenuated voltage; and

a detection block comparing a digital signal generated based on the attenuated voltage with at least one reference code and generating the control signal based on the comparison result.

5. The detection device of claim 4, wherein the detection block comprises:

an analog-to-digital converter converting the attenuated voltage from an analog signal into the digital signal; and

a central processing unit comparing the digital signal with a predetermined minimum code and a predetermined maximum code, and generating the control signal.

6. The detection device of claim 1, wherein the detector generates the control signal for increasing the induced current until the strength of the induced voltage is at least a predetermined first strength.

7. The detection device of claim 6, wherein the detector generates the control signal for decreasing the induced current until the strength of the induced voltage is equal to or less than a predetermined second strength,

wherein the predetermined second strength is greater than the predetermined first strength.

8. The detection device of claim 1, wherein the transmitter comprises:

a driver including at least one pull-up transistor and at least one pull-down transistor, and the driver driving the induced current; and

a current controller controlling the driver in response to the control signal.

10. The detection device of claim 1, wherein the detection device detects whether a near-far field communication (NFC) device is positioned within a predetermined range of the detection device, and communicates with the NFC device.

9. (canceled)

11. (canceled)

12. A communication system, comprising:

an antenna;

a card detection device supplying an induced current to the antenna, monitoring a strength of an induced voltage of the antenna, adjusting the strength of the induced voltage generated in the antenna by adjusting the induced current supplied to the antenna, detecting whether a card is positioned within a predetermined range of the communication system, and generating a wake-up signal; and

a receiver being in a power-down state when the card is positioned out of the predetermined range of the communication system,

wherein the receiver wakes up in response to the wake-up signal, and communicates with the card.

13. The communication system of claim 12, wherein the card detection device monitors the strength of the induced voltage of the antenna and adjusts the induced current to a target current in a current adjusting mode,

wherein the card detection device detects whether the card is positioned within the predetermined range of the communication system in a mode which is not the current adjusting mode.

14. The communication system of claim 13, wherein the card detection device comprises:

a transmitter adjusting the strength of the induced voltage generated in the antenna by adjusting the induced current; and

a card detector monitoring the strength of the induced voltage of the antenna and generating a control signal for controlling the induced current to the antenna based on the monitored strength of the induced voltage of the antenna.

15. The communication system of claim 14, wherein the card detector comprises:

a rectifier rectifying the induced voltage and generating a rectified voltage;

an attenuator attenuating the rectified voltage and generating an attenuated voltage; and

a detection block comparing at least one voltage generated based on the attenuated voltage with at least one reference voltage and generating the control signal based on the comparison result.

16. The communication system of claim 15, wherein the detection block comprises:

a first comparator comparing a first voltage obtained by dividing the attenuated voltage with a first reference voltage;

a second comparator comparing a second voltage obtained by dividing the attenuated voltage with a second reference voltage; and

a controller generating the current control signal based on output signals of the first and second comparators.

17. The communication system of claim 14, wherein the card detector comprises:

a rectifier rectifying the induced voltage and generating a rectified voltage;

an attenuator attenuating the rectified voltage and generating an attenuated voltage; and

a detection block comparing a digital signal generated based on the attenuated voltage with at least one reference code and generating the control signal based on the comparison result.

19. The communication system of claim 14, wherein the card detector generates the control signal for increasing the induced current until the strength of the induced voltage is at least a predetermined first strength,

wherein the card detector generates the control signal for decreasing the induced current until the strength of the induced voltage is equal to or less than a predetermined second strength, and

wherein the predetermined second strength is greater than the predetermined first strength.

20. The communication system of claim 14, wherein the transmitter comprises:

a driver including at least one pull-up transistor and at least one pull-down transistor, and the driver driving the induced current; and

a current controller controlling at least one among a power supply voltage applied to the driver, or gate voltages of the at least one pull-up transistor and at least one pull-down transistor in response to the control signal.

18. (canceled)

21-23. -23. (canceled)

24. A near-field communication (NFC) system, comprising:

a reader module including a transmitter and an NFC device detector, wherein the reader module transitions from a power-down state to a power-up state when an NFC device is detected within a predetermined range of the NFC system and communicating with the NFC device; and

an antenna,

wherein the transmitter supplies an induced current to the antenna and adjusts a strength of an induced voltage generated in the antenna by adjusting the induced current in response to a control signal output from the NFC device detector,

wherein the NFC device detector detects the strength of the induced voltage of the antenna, determines whether to adjust the induced current, and outputs the control signal for controlling the induced current to the antenna to the transmitter based on the detected strength of the induced voltage of the antenna.

25. The system of claim 24, wherein the NFC device detector detects the NFC device positioned in the predetermined range of the NFC system based on a change of the induced voltage.

26. The system of claim 24, wherein the NFC device detector outputs the control signal for adjusting the induced current when the induced voltage is not in a predetermined target range.