Electronic device and control method for the same

• US 6,469,472 B1
• Filed: 11/17/2000
• Issued: 10/22/2002
• Est. Priority Date: 03/18/1999
• Status: Expired due to Term

• Current Assignee: Chamiraux Management LLC
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Aoshima, Ichiro, Honda, Katsuyuki, Hayakawa, Motomu, Kosuda, Tsukasa
• Primary Examiner(s): Tso, Edward H.
• Assistant Examiner(s): TIBBITS, PIA FLORENCE
• Application Number:
  US09/700,902
• Time in Patent Office: 704 Days
• Field of Search: 320/122, 340/870.31
• US Class Current: 320/122
• CPC Class Codes: H02J 50/05 using capacitive coupling
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 7/0044 specially adapted for holding portable devices containing batteries H02J7/0045 takes precedence
• CPC Class Codes: H02J 7/342 The other DC source being a battery actively interacting with the first one, i.e. battery to battery charging with circuits for polarity protection H02J7/0034

Abstract

In an electronic device in which a charge path to a secondary battery and a signal path to a reception device are partially shared and a receiving-time current due to the reception is made to be a charging current for the secondary battery, even in a case in which the voltage across the secondary battery is close to a maximum voltage, by bypassing the charging current due to the signal reception, the voltage across the secondary battery is controlled so as not to exceed the maximum voltage.

Claims

1. An electronic device comprising:

a charge storage device for storing power transferred from outside said electronic device, said charge storage device being characterized by a predetermined, maximum voltage rating;

a reception device for receiving data signals from outside said electronic device; and

a charging-current-control device for controlling a charging current applied to said charge storage device so as not to exceed said maximum voltage; and

wherein reception of said data signals by said reception device causes charging of said charge storage device by using part of a signal path for conveying said data signals to said reception device as part of a charging path for conveying said charging current to said charge storage device.

2. An electronic device according to claim 1, characterized in that said charging-current-control device is provided with a charging-current-bypass device for bypassing a predetermined amount of said charging current away from said charge storage device.

3. An electronic device according to claim 2, characterized in that said charging-current-bypass device is provided with:

a resistance element; and

a switch device for allowing said resistance element to be selectively connected in parallel with said charge storage device.

4. An electronic device according to claim 3, characterized in that said charging-current-control device further includes:

an internal resistance detection device for measuring the internal resistance of said charge storage device; and

a resistance control device for controlling the resistance of said resistance element based on the measured internal resistance of said charge storage device.

5. An electronic device according to claim 2, characterized in that said charging-current-bypass device is provided with:

a plurality of resistance elements; and

a switching device for allowing at least one of said plurality of resistance elements to be connected in parallel with said charge storage device.

6. An electronic device according to claim 5, characterized in that said charging-current-control device is provided with:

an internal resistance measuring device for measuring the internal resistance of said charge storage device; and

a switch control device for controlling said switching device and thereby determining the number of said resistance elements placed in parallel with said charge storage device based on the measured internal resistance of said charge storage device.

7. An electronic device according to claim 2, characterized in that said charging-current-bypass device is provided with:

a variable resistance element; and

a resistance control device for setting the resistance value of said variable resistance element based on the magnitude of said charging current or said maximum voltage rating.

8. An electronic device according to claim 7 characterized in that:

said charging-current-control device is provided with an internal resistance measuring device for measuring the internal resistance of said charge storage device; and

said resistance control device further controls the resistance of said variable resistance element based additionally on the measured internal resistance of said charge storage device.

9. An electronic device according to claim 2, wherein said charging-current-bypass device includes a bypass switching device for forming a current-bypass path only when said reception device is receiving data signals.

10. An electronic device according to claim 1, characterized in that:

said data signals include a start bit signal indicating the start a data unit transfer; and

said charging-current-control device starts to control said charging current based upon reception of said start bit signal.

11. An electronic device according to claim 10, characterized in that said charging-current-control device terminates the control of said charging current upon completion of the data unit transfer initiated by said start bit signal.

12. An electronic device according to claim 1, characterized in that said charging-current-control device modifies its control of said charging current in accordance to one of multiple signal transfer modes received at said reception device, wherein each signal transfer mode is identified by the data transfer pattern of said data signals.

13. An electronic device according to claim 1, characterized in that:

said charging-current-control device includes;

an accumulated voltage detection device for monitoring the accumulated voltage across said charge storage device; and

a voltage comparing device for comparing the accumulated voltage across said charge storage device with a reference voltage of lesser magnitude than said maximum voltage;

wherein said charging-current-control device activates its control of said charging current when the accumulated voltage of said charge storage device exceeds said reference voltage.

14. An electronic device comprising:

a charge storage device for storing power transferred from outside said electronic device, said charge storage device being characterized by a predetermined maximum voltage rating;

a reception circuit for receiving data signals from outside said electronic device;

wherein reception of said data signals by said reception device causes charging of said charge storage device by using part of a signal path for conveying said data signals to said reception device as part of a charging path for conveying charging current to said charge storage device; and

an energy balance control device for controlling the accumulated voltage across said charge storage device so as not to exceed said maximum voltage, wherein said energy balance control device includes a data return device for draining charge from said charge storage device by transmitting a return-data pattern, and wherein said energy balance control device maintains a balance between charge stored into said charge storage device and charge discharged from said charge storage device by controlling the amount of data transmissions by said data return device.

15. An electronic device according to claim 14, wherein said return-data pattern is dependent on the data pattern of data signals received by said reception circuit.

16. An electronic device according to claim 15, wherein said data return device generates said return-data pattern to be identical to the data pattern of the received data signals.

17. An electronic device according to claim 15, characterized in that said data return device selects, as said return-data pattern, one of plurality of a predetermined data patterns based on the cumulative energy of the received data signals.

18. An electronic device according to claim 14, further including:

a data transmission device having multiple transmission modes, each of said transmission modes requiring a different amount of energy usage from said charge storage device; and

wherein said energy balance control device selects, based on the accumulated voltage across said charge storage device, one of said multiple transmission modes for responding to data signals received by said reception device.

19. An electronic device according to claim 18, wherein:

if the accumulated voltage across said charge storage device is higher than a predetermined first reference voltage, then said energy balance control device selects a transmission mode that will require a larger amount of energy to respond to said received data signals than the amount of energy charged into said charge storage device during the reception of said data signals; and

if the accumulated voltage across said storage device is lower than a predetermined second reference voltage, then said energy balance control device selects a transmission mode that will require a smaller amount of energy to respond to said received data signals than the amount of energy charged into said charge storage device during the reception of said data signals.

20. An electronic device according to claim 14, characterized in that said energy balance control device wherein said return-data pattern is dependent on the received data;

and wherein said energy balance control device further includes a discharging-current-control device for controlling the discharging current of said storage device when said return-data pattern is transmitted.

21. An electronic device according to claim 20, characterized in that said discharging-current-control device includes:

a plurality of resistance elements;

a resistance selection and insertion device for selecting any one of or a plurality of resistance elements from among said plurality of resistance elements in accordance with the discharging current to be set and inserting the selected resistance element into a discharging path.

22. An electronic device according to claim 20, characterized in that said discharging-current-control device includes:

a variable resistance element provided in the discharging path having a variable resistance; and

a resistance control device for controlling the resistance of said variable resistance element based on the discharging current to be set.

23. An electronic device comprising:

a charge storage device for storing power transferred from outside said electronic device, said charge storage device being characterized by a predetermined maximum voltage rating;

a reception circuit for receiving data signals from outside said electronic device;

wherein reception of said data signals by said reception device causes charging of said charge storage device by using part of a signal path for conveying said data signals to said reception device as part of a charging path for conveying charging current to said charge storage device; and

a charging-current-control device having;

an accumulated voltage measuring device for measuring the accumulated voltage across said charge storage device; and

a switching device provided between said reception device and said charge storage device for causing said reception device and said storage device to be disconnected when said accumulated voltage measured by said accumulated voltage measuring device exceeds said maximum voltage.

24. A control method for an electronic device including a charge storage device characterized by a predefined maximum voltage rating and effective for storing power transferred from outside said electronic device, and a reception circuit for receiving data signals from outside said electronic device, whereby reception of said data signals by said reception device causes charging of said charge storage device by using part of a signal path for conveying said data signals to said reception device as part of a charging path for conveying charging current to said charge storage device, said control method comprising:

a voltage measuring step for measuring the voltage across said charge storage device; and

a charging-current-bypass step for controlling the voltage across said charge storage device so as not to exceed said maximum voltage by bypassing the charging current away from said charge storage device by a predetermined amount based on the measured voltage across said charge storage device.