Power-Saving Wireless Input Device and System

• US 20090179761A1
• Filed: 12/22/2008
• Published: 07/16/2009
• Est. Priority Date: 01/15/2008
• Status: Active Grant

• Current Assignee: Xueshan Technologies Inc. (Wi-LAN Inc.)
• Original Assignee: MStar Semiconductor Incorporated (MediaTek, Inc.)
• Inventors: Chen, Chien-Sheng, Chang, Wei
• Granted Patent: US 8,120,487 B2
• Time in Patent Office: Days
• US Class Current: 340/572.100
• CPC Class Codes: G06F 1/32 Means for saving power
• CPC Class Codes: G06F 3/038 Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry
• CPC Class Codes: H04B 5/0031 for data transfer
• CPC Class Codes: H04B 5/0037 for power transfer
• CPC Class Codes: H04B 5/0062 in RFID [Radio Frequency Identification] Systems
• CPC Class Codes: H04B 5/02 using transceiver
• CPC Class Codes: H04B 5/48 Transceivers
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04B 5/77 for interrogation
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer
• CPC Class Codes: H04W 52/0296 switching to a backup power supply
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A power-saving wireless input device and an associated system are included. The wireless input device comprises an antenna, an RFID transponder, an energy-storing unit, and a sensing unit. The RFID transponder receives an AC signal via the antenna, and converts the AC signal into a DC signal. The energy-storing unit receives the DC signal for charging. The sensing unit, which is powered by the energy-storing unit, generates an input signal to the RFID transponder. The RFID transponder demodulates the AC signal to generate a request signal, and performs load modulation according to the input signal to generate a reply signal in response to the request signal. The reply signal is then transmitted via the antenna.

Claims

1. A wireless input device, comprising:

an antenna;

a radio frequency identification (RFID) transponder, for receiving an AC signal via the antenna;

a power supply unit, coupled to the RFID transponder; and

a sensing unit, powered by the power supply unit, for generating an input signal to the RFID transponder;

wherein, the RFID transponder demodulates the AC signal to generate a request signal, and performs load modulation according to the input signal to generate a reply signal in response to the request signal, followed by transmitting the reply signal via the antenna.

2. The wireless input device according to claim 1, wherein the input signal is an input signal from a mouse device, an input signal from a keyboard, or a sensing signal from a sensing device.

3. The wireless input device according to claim 1, wherein the power supply unit is a battery.

4. The wireless input device according to claim 1, wherein the RFID transponder comprises a rectifier circuit for converting the AC signal to a DC voltage, and the power supply unit is an energy-storing unit for receiving the DC voltage for charging.

5. The wireless input device according to claim 4, wherein the energy-storing unit comprises a chargeable battery.

6. The wireless input device according to claim 4, further comprising:

a battery for providing electric energy to the RFID transponder and the sensing unit.

7. The wireless input device according to claim 6, wherein a usage priority of electric energy of the energy-storing unit precedes a usage priority of electric energy of the battery.

8. The wireless input device according to claim 1, wherein the power supply unit is a rectifier energy-storing unit, which receives the AC signal via the antenna and converts the AC signal to a DC voltage for charging.

9. The wireless input device according to claim 8, further comprising:

a battery for providing electric energy to the RFID transponder and the sensing unit.

10. The wireless input device according to claim 1, wherein the RFID transponder comprises:

a demodulation circuit for demodulating the AC signal to generate the request signal;

a control circuit, receiving the request signal, for converting the input signal to input data, and for generating a corresponding control signal according to the input data; and

a modulation circuit for performing load modulation according to the control signal to generate the reply signal.

11. The wireless input device according to claim 10, wherein the RFID transponder further comprises:

a memory unit coupled to the control circuit and for storing the input data.

12. A wireless input system, comprising:

an electronic device;

an RF transceiver, coupled to the electronic device, for transmitting a first RF signal; and

a wireless input device, for receiving the first RF signal to generate electric energy, and for modulating an input signal to generate a second RF signal associated with the input signal,

wherein the RF transceiver receives the second RF signal, and demodulates the second RF signal to a baseband signal to be transmitted to the electronic device.

13. The wireless input system according to claim 12, wherein the RF transceiver is an RFID transceiver, and the wireless input device comprises:

an RFID transponder for demodulating the first RF signal to generate a request signal;

a power supply unit, coupled to the RFID transponder; and

a sensing unit, utilizing electric energy provided by the power supply unit to generate the input signal to be transmitted to the RFID transponder,

wherein the RFID transponder performs load modulation according to the input signal to generate the second RF signal in response to the request signal.

14. The wireless input system according to claim 13, wherein the power supply unit is a battery.

15. The wireless input system according to claim 13, wherein the RFID transponder converts the first RF signal to a DC voltage, and the power supply unit is an energy-storing unit for receiving the DC voltage for charging.

16. The wireless input system according to claim 15, wherein the wireless input device further comprises a battery for providing electric energy to the RFID transponder and the sensing unit.

17. The wireless input system according to claim 16, wherein a usage priority of electric energy of the energy-storing unit precedes a usage priority of electric energy of the battery.

18. The wireless input system according to claim 13, wherein the power supply unit is a rectifier energy-storing unit for converting the first RF signal to a DC voltage for charging.

19. The wireless input system according to claim 18, wherein the wireless device further comprises a battery for providing electric energy to the RFID transponder and the sensing unit.

20. The wireless input system according to claim 12, wherein the wireless input device is a wireless mouse device, a wireless keyboard, or a sensing device.