Cordless telephone system having power interruption detection

• US 5,867,798 A
• Filed: 12/17/1996
• Issued: 02/02/1999
• Est. Priority Date: 11/22/1993
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Ishihara, Takeshi, Taura, Katsuhiro, Inukai, Shinichiro
• Primary Examiner(s): CUMMING, WILLIAM D
• Application Number:
  US08/768,224
• Time in Patent Office: 777 Days
• Field of Search: 379/61, 320/14, 320/21, 320/20, 320/35, 320/30, 320/2, 455/573
• US Class Current: 455/573
• CPC Class Codes: H02J 7/00036 Charger exchanging data with battery
• CPC Class Codes: H02J 7/00047 with provisions for charging different types of batteries
• CPC Class Codes: H02J 7/0036 using connection detecting circuits H02J7/0034 takes precedence
• CPC Class Codes: H02J 7/0044 specially adapted for holding portable devices containing batteries H02J7/0045 takes precedence

Abstract

In a cordless telephone system having a mobile telephone set and a charging stand, the mobile telephone set includes at least one charging terminal and a charging control terminal, and control circuitry for monitoring the at least one charging terminal and the charging control terminal, and controlling whether or not the mobile telephone set is permitted to operate in a quick communication mode. The quick communication mode is a communication mode of the mobile telephone set in which the mobile telephone set automatically begins to transmit an outgoing call of the telephone system or to receive an incoming call, when the mobile telephone set is picked up from the charging stand.

Claims

1. In a cordless telephone system having a mobile telephone set and a charging stand for supplying power to the mobile telephone set when the mobile set is placed on the charging stand, the mobile telephone set including:

a charging terminal and a charging control terminal; and

control means for

monitoring for a change in voltage at the charging terminal of the mobile telephone set after the mobile telephone set has been placed on the charging stand,

monitoring for a change in the voltage at the charging control terminal of the mobile telephone set if the voltage at the charging terminal changes to a predetermined value,

operating the mobile telephone set in a quick communication mode if the voltage at the charging terminal and the voltage at the charging control terminal both change to the predetermined value substantially simultaneously, the quick communication mode being a communication mode in which the mobile telephone set starts to originate an outgoing call or to answer an incoming call when the mobile telephone set is taken up from the charging stand, and

deciding that the mobile telephone set is no longer receiving power from the charging stand even though it has not been taken up from the charging stand if the voltage at the charging terminal changes to the predetermined value but the voltage at the charging control terminal does not change to the predetermined value substantially simultaneously.

2. A cordless telephone system comprising:

a mobile telephone set having at least one charging terminal and a charging control terminal, and

a charging stand for supplying a charging voltage to terminals of the mobile telephone set,

wherein the charging stand includes first control means for reducing the charging voltage supplied to the charging control terminal of the mobile telephone set to a low level after a lapse of a predetermined time period when the first control means detects stopping of generation of the charging voltage from a DC voltage supply, the stopping including interruption of a supply of power to the DC voltage supply from an external AC power source, and

wherein the mobile telephone set includes second control means for;

(a) permitting the mobile telephone set to operate in a quick communication mode when the second control means detects that supply of the charging voltage to both of the at least one charging terminal and the charging control terminal of the mobile telephone set are simultaneously stopped, and

(b) not permitting the mobile telephone set to operate in the quick communication mode when the second control means detects that a time period of stopping to supply the charging voltage to the charging control terminal is longer than a time period of stopping to supply the charging voltage to the at least one charging terminal, and

wherein the quick communication mode is a communication mode of the mobile telephone set in which the mobile telephone set starts to originate an outgoing call or to answer an incoming call, when the mobile telephone set is taken up from the charging stand.

3. A cordless telephone system according to claim 2, wherein the at least one charging terminal comprises a positive charging terminal and a negative charging terminal, and,

wherein, when the mobile telephone set is unloaded from the charging stand, the negative charging terminal is electrically opened earlier than the positive charging terminal.

4. A cordless telephone system comprising:

a mobile telephone sets, and

a charging stand,

wherein the charging stand includes;

a first charging terminal and a first charging control terminal, for supplying to the mobile telephone set a charging voltage generated from a DC power supply connected to an AC power source, and

first control means for reducing the charging voltage supplied to the first charging control terminal to a low level after a lapse of a predetermined time period when the first control means detects stopping of generation of the charging voltage from the DC power supply including interruption of supply of power from the AC power source,

wherein the mobile telephone set includes;

a second charging terminal and a second charging control terminal, for supplying the charging voltage to a built-in battery received through the first charging terminal and the first charging control terminal, and

second control means for;

(a) permitting the mobile telephone set to operate in a quick communication mode when the second control means detects that supply of the charging voltage to both the first charging terminal and the first charging control terminal is simultaneously stopped, and

(b) not permitting the mobile telephone set to operate in the quick communication mode when the second control means detects that the time period of stopping to supply the charging voltage to the second charging control terminal is longer than the time period of stopping to supply the charging voltage to the second charging terminal, and

wherein the quick communication mode is a communication mode of the mobile telephone set in which the mobile telephone set starts to originate an outgoing call or to answer an incoming call, when the mobile telephone set is taken up from the charging stand.

5. A cordless telephone system according to claim 4, wherein the second charging terminal is a second positive charging terminal, and

wherein, when the mobile telephone set is unloaded from the charging stand, a third, negative charging terminal is electrically opened earlier than the second, positive charging terminal.

6. A cordless telephone system comprising:

a mobile telephone set, and

a charging stand,

wherein the charging stand includes voltage supply means for supplying a charging voltage to the mobile telephone set, and

wherein the mobile telephone set includes;

a battery charged by the charging voltage supplied from the voltage supply means,

a reverse current blocking diode for preventing flow of a reverse current to the voltage supply means from the battery, and

control means for permitting the mobile telephone set to operate in a quick communication mode, in which the mobile telephone set starts to originate an outgoing call or to answer an incoming call when the mobile telephone set is take up from the charging stand, if it is detected that the voltage supply means is supplying the charging voltage, and for not permitting the mobile telephone set to operate in the quick communication mode if it is detected that the voltage supply means is not supplying the charging voltage.

7. A cordless telephone system according to claim 6, wherein the charging stand includes charging control means for supplying a voltage lower than a discharge termination voltage to the battery after the battery is completely charged.

8. A cordless telephone system according to claim 6, wherein the battery is of lithium ion type.

9. A cordless telephone system according to claim 7, wherein the battery is of lithium ion type.

10. A method of controlling a cordless telephone system which includes a mobile telephone set and a charging stand for supplying a charging voltage and a control signal to the mobile telephone set when the mobile telephone set is placed on the charging stand, comprising the steps of:

(a) in the mobile telephone set, monitoring for changes in the charging voltage and the control signal after the mobile telephone set has been placed on the charging stand;

(b) operating the mobile telephone set in a quick communication mode if substantially simultaneous changes occur in both the charging voltage and the control signal, the quick communication mode being a communication mode in which the mobile telephone set starts to originate an outgoing call or to answer an incoming call when the mobile telephone set is taken up from the charging stand; and

(c) deciding that the mobile telephone set is no longer receiving the charging voltage from the charging stand even though it has not been taken up from the charging stand if the charging voltage changes but the control signal does not also change substantially simultaneously.

11. A method of controlling a cordless telephone system which includes a mobile telephone set and a charging stand for supplying power to the mobile telephone set when the mobile telephone set is placed on the charging stand, the mobile telephone set having a charging terminal and a charging control terminal, comprising the steps of:

(a) monitoring for a change in voltage at the charging terminal of the mobile telephone set after the mobile telephone set has been placed on the charging stand;

(b) monitoring for a change in voltage at the charging control terminal of the mobile telephone set if the voltage at the charging terminal changes to a predetermined value;

(c) operating the mobile telephone set in a quick communication mode if the voltage at the charging terminal and the voltage at the charging control terminal both change to the predetermined value substantially simultaneously, the quick communication mode being a communication mode in which the mobile telephone set starts to originate an outgoing call or to answer an incoming call when the mobile telephone set is taken up from the charging stand; and

(d) deciding that the mobile telephone set is no longer receiving power from the charging stand even though it has not been taken up from the charging stand if the voltage at the charging terminal changes to the predetermined value but the voltage at the charging control terminal does not changes to the predetermined value substantially simultaneously.

12. The method of claim 11, wherein the predetermined value is zero volts.

13. The method of claim 11, wherein the charging terminal is a first charging terminal, wherein the mobile telephone set additionally has a second charging terminal, wherein the charging stand has first and second charging terminals and a charging control terminal which respectively contact the first charging terminal, the second charging terminal, and the charging control terminal of the mobile telephone set when the mobile telephone set is placed on the charging stand, and wherein the method further comprises the step of breaking contact between the second charging terminals of the mobile telephone set and the charging stand before breaking contact between the first charging terminals and the control terminals of the mobile telephone set and the charging stand when the mobile telephone set is taken up from the charging stand.