ELECTRONIC APPARATUS

• US 20080215265A1
• Filed: 01/28/2008
• Published: 09/04/2008
• Est. Priority Date: 02/05/2007
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Tohyama, Kei
• Granted Patent: US 7,974,795 B2
• Time in Patent Office: Days
• US Class Current: 702/63
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm
• CPC Class Codes: G01R 31/3828 using current integration

Abstract

When discharge power calculated based on a current value detected by a current detector is smaller than expected maximum power, which is the maximum power expected in an actual operation, a discharge efficiency at the expected maximum power is set as a discharge efficiency used for remaining capacity calculation. This ensures that a remaining capacity based on power required for a photographing operation can be detected.

Claims

1. An electronic apparatus comprising:

a discharge current detecting unit configured to detect a discharge current value of a battery;

a battery voltage detecting unit configured to detect a voltage value of the battery when the battery is discharged;

a temperature detecting unit configured to detect a temperature of the battery;

a discharge power calculation unit configured to calculate a discharge power value on the basis of the discharge current value detected by the discharge current detecting unit and the voltage value detected by the battery voltage detecting unit;

a determination unit configured to determine whether or not the discharge power value calculated by the discharge power calculation unit is smaller than a predetermined specified power value;

a discharge efficiency calculation unit configured to calculate a discharge efficiency from the specified power value and the temperature detected by the temperature detecting unit when the determination unit determines that the calculated discharge power value is smaller than the specified power value, and to calculate a discharge efficiency from the calculated discharge power value and the temperature detected by the temperature detecting unit when the determination unit determines that the calculated discharge power value is greater than the specified power value; and

a remaining capacity calculation unit configured to calculate a remaining capacity of the battery on the basis of the discharge efficiency calculated by the discharge efficiency calculation unit.

2. The electronic apparatus according to claim 1, wherein the remaining capacity calculation unit divides the calculated remaining capacity by a capacity of the battery that is fully charged to calculate a relative remaining capacity of the battery.

3. The electronic apparatus according to claim 1, wherein the electronic apparatus is an electronic apparatus including a motor, and

the specified power value is specified on the basis of a power value obtained when the motor is being driven.

4. The electronic apparatus according to claim 1, wherein the electronic apparatus is an electronic apparatus having a plurality of operation modes, and

the specified power value is specified on the basis of the operation modes.

5. The electronic apparatus according to claim 1, wherein the electronic apparatus is an image pickup device having a plurality of autofocus modes, and

the specified power value is specified on the basis of the autofocus modes.

6. The electronic apparatus according to claim 1, wherein the electronic apparatus is an electronic apparatus connectable to an external device, and

the specified power value is specified on the basis of whether or not there is an external device connected to the electronic apparatus.

7. The electronic apparatus according to claim 1, wherein the electronic apparatus is an image pickup device including a replaceable lens, and

the specified power value is specified on the basis of the type of a lens attached to the electronic apparatus.

8. An electronic apparatus comprising:

a discharge current detecting unit configured to detect a discharge current value of a battery;

a temperature detecting unit configured to detect a temperature of the battery;

a determination unit configured to determine whether or not the discharge current value detected by the discharge current detecting unit is smaller than a predetermined specified current value;

a discharge efficiency calculation unit configured to calculate a discharge efficiency from the specified current value and the temperature detected by the temperature detecting unit when the determination unit determines that the detected discharge current value is smaller than the specified current value, and to calculate a discharge efficiency from the detected discharge current value and the temperature detected by the temperature detecting unit when the determination unit determines that the detected discharge current value is greater than the specified current value; and

a remaining capacity calculation unit configured to calculate a remaining capacity of the battery on the basis of the discharge efficiency calculated by the discharge efficiency calculation unit.

9. The electronic apparatus according to claim 8, wherein the remaining capacity calculation unit divides the calculated remaining capacity by a capacity of the battery that is fully charged to calculate a relative remaining capacity.

10. The electronic apparatus according to claim 8, wherein the electronic apparatus is an electronic apparatus including a motor, and

the specified current value is specified on the basis of a power value obtained when the motor is being driven.

11. The electronic apparatus according to claim 8, wherein the electronic apparatus is an electronic apparatus having a plurality of operation modes, and

the specified current value is specified on the basis of the operation modes.

12. The electronic apparatus according to claim 8, wherein the electronic apparatus is an image pickup device having a plurality of autofocus modes, and

the specified current value is specified on the basis of the autofocus modes.

13. The electronic apparatus according to claim 8, wherein the electronic apparatus is an electronic apparatus connectable to an external device, and

the specified current value is specified on the basis of whether or not there is an external device connected to the electronic apparatus.

14. The electronic apparatus according to claim 8, wherein the electronic apparatus is an image pickup device including a replaceable lens, and

the specified current value is specified on the basis of the type of a lens attached to the electronic apparatus.

15. A method for controlling an electronic apparatus including a discharge current detecting unit configured to detect a discharge current value of a battery, a battery voltage detecting unit configured to detect a voltage value of the battery when the battery is discharged, a temperature detecting unit configured to detect a temperature of an environment where the battery is located, and a discharge power calculation unit configured to calculate a discharge power value on the basis of the discharge current value detected by the discharge current detecting unit and the voltage value detected by the battery voltage detecting unit, the method comprising:

determining whether or not the discharge power value calculated by the discharge power calculation unit is smaller than a predetermined specified power value;

calculating a discharge efficiency on the basis of the specified power value and the temperature detected by the temperature detecting unit when it is determined in the determination step that the calculated discharge power value is smaller than the specified power value, and calculating a discharge efficiency on the basis of the calculated discharge power value and the temperature detected by the temperature detecting unit when it is determined in the determination step that the calculated discharge power value is greater than the specified power value; and

calculating a remaining capacity of the battery on the basis of the calculated discharge efficiency.

16. A method for controlling an electronic apparatus including a discharge current detecting unit configured to detect a discharge current value of a battery, and a temperature detecting unit configured to detect a temperature of the battery, the method comprising:

determining whether or not the discharge current value detected by the discharge current detecting unit is smaller than a predetermined specified current value;

calculating a discharge efficiency on the basis of the specified current value and the temperature detected by the temperature detecting unit when it is determined in the determination step that the detected discharge current value is smaller than the specified current value, and calculating a discharge efficiency on the basis of the detected discharge current value and the temperature detected by the temperature detecting unit when it is determined in the determination step that the detected discharge current value is greater than the specified current value; and

calculating a remaining capacity of the battery on the basis of the calculated discharge efficiency.