Video camera with low battery warning

• US 7,102,684 B1
• Filed: 02/23/2000
• Issued: 09/05/2006
• Est. Priority Date: 02/26/1999
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Higuchi, Yoshinari, Ieki, Shinji, Ebato, Satoshi
• Primary Examiner(s): Ho, Tuan
• Assistant Examiner(s): YODER III, CHRISS S
• Application Number:
  US09/510,856
• Time in Patent Office: 2,386 Days
• Field of Search: 348/372, 348/333.02, 320/106, 320/125, 320132-136
• US Class Current: 348/372
• CPC Class Codes: H04N 23/634 Warning indications
• CPC Class Codes: H04N 23/65 Control of camera operation in relation to power supply

Abstract

A warning is displayed for a constant time prior to end of a battery with respect to battery packs having various cell structures. A microcomputer 14 in the side of a video camera recorder body 10 obtains a reference voltage value from a voltage correction value decided based on information concerning a capacity of a cell in a battery pack obtained from a battery pack 20, and an end voltage value at which use of the battery is ended. A display section 15 is controlled by a result of comparison between the voltage value of the battery pack 20 and the reference voltage value, and a warning is displayed when the voltage value of the battery pack becomes equal to or lower than the reference voltage value.

Claims

1. A video camera, comprising:

obtaining means for obtaining a capacity value of a battery by communicating via a communications line with a battery pack that contains the battery, the battery providing power to the video camera, the capacity value indicating a number of cell structures in the battery;

setting means for setting a correction value based on the capacity value;

correcting means for correcting a low power warning voltage value by subtracting the correction value from the low power warning voltage value;

generating means for generating a low power warning when a detected battery voltage is less than or equal to the corrected low power warning voltage value and for generating a residual power indication when the detected battery voltage is greater than the corrected low power warning voltage value; and

display means for displaying the low power warning or the residual power indication.

2. A video camera as claimed in claim 1, further comprising detecting means for detecting the battery voltage.

3. A video camera as claimed in claim 1, further comprising storage means for storing the capacity value, said obtaining means obtaining the capacity value from said storage means.

4. A video camera as claimed in claim 1, further comprising determining means for determining a residual power amount of the battery based on the capacity value.

5. A video camera as claimed in claim 4, wherein said generating means generates a display of the residual power amount as the residual power indication when the detected battery voltage is greater than the corrected low power warning voltage value.

6. A video camera as claimed in claim 1, wherein said generating means generates the low power warning when the detected battery voltage is greater than a minimum operating voltage.

7. A video camera as claimed in claim 1, wherein the correction value is a first value when the capacity value exceeds a first predetermined value that is the capacity value of a battery having a first known number of cell structures, the correction value is a second value when the capacity value does not exceed the first predetermined value but exceeds a second predetermined value that is the capacity value of a battery having a second known number of cell structures, the first known number of cell structures being greater than the second known number of cell structures, and the correction value is zero when the capacity value does not exceed the second predetermined value.

8. A video system, comprising:

a video camera body;

a battery pack including a battery having at least one battery cell; and

a communications line connected to said video camera body and said battery pack;

said video camera body including;

obtaining means for obtaining a capacity value of said battery by communicating with said battery pack via said communications line, the capacity value indicating a number of cell structures in the battery,

setting means for setting a correction value based on the capacity value,

correcting means for correcting a low power warning voltage value by subtracting the correction value from the low power warning voltage value,

generating means for generating a low power warning when a detected battery voltage is less than or equal to the corrected low power warning voltage value and for generating a residual power indication when the detected battery voltage is greater than the corrected low power warning voltage value, and

display means for displaying the low power warning or the residual power indication.

9. A video system as claimed in claim 8, wherein said battery pack includes storage means for storing the capacity value, said obtaining means of said video camera body obtaining the capacity value from the storage means.

10. A video system as claimed in claim 8, wherein said video camera body includes detecting means for detecting the battery voltage.

11. A video system as claimed in claim 8, wherein the correction value is a first value when the capacity value exceeds a first predetermined value that is the capacity value of a battery having a first known number of cell structures, the correction value is a second value when the capacity value does not exceed the first predetermined value but exceeds a second predetermined value that is the capacity value of a battery having a second known number of cell structures, the first known number of cell structures being greater than the second known number of cell structures, and the correction value is zero when the capacity value does not exceed the second predetermined value.

12. A method of detecting low power in a battery, comprising:

detecting a battery voltage;

obtaining a capacity value of the battery by communicating with a battery pack that contains the battery, the capacity value indicating a number of cell structures in the battery;

setting a correction value based on the capacity value;

correcting a low power warning voltage value by subtracting the correction value from the low power warning voltage value;

generating a low power warning when the battery voltage is less than or equal to the corrected low power warning voltage value;

generating a residual power indication when the detected battery voltage is greater than the corrected low power warning voltage value; and

displaying the low power warning or the residual power indication.

13. A method as claimed in claim 12, further comprising storing the capacity value, said step of obtaining the capacity value including obtaining the stored capacity value.

14. A method as claimed in claim 12, further comprising determining a residual power amount of the battery based on the capacity value.

15. A method as claimed in claim 14, further comprising generating a display of the residual power amount as the residual power indication when the battery voltage is greater than the corrected low power warning voltage value.

16. A method as claimed in claim 12, wherein said generating step includes generating the low power warning when the battery voltage is greater than a minimum operating voltage.

17. A method as claimed in claim 12, wherein the correction value is a first value when the capacity value exceeds a first predetermined value that is the capacity value of a battery having a first known number of cell structures, the correction value is a second value when the capacity value does not exceed the first predetermined value but exceeds a second predetermined value that is the capacity value of a battery having a second known number of cell structures, the first known number of cell structures being greater than the second known number of cell structures, and the correction value is zero when the capacity value does not exceed the second predetermined value.

18. A battery pack for a video system, said battery pack comprising:

a cell structure section including at least one battery cell and having at least one stage;

power terminal means for supplying power to a video camera body of the video system over a power source line;

storage means for storing a capacity value of said battery, the capacity value indicating a number of battery cells in said battery;

communications terminal means for providing a connection to a communications line connected between said battery pack and the video camera body; and

providing means for providing the capacity value stored in said storage means to the video camera body using said communications terminal means and the communications line;

whereby said video camera body sets a correction value based on the provided capacity value, corrects a low power warning voltage value by subtracting the correction value from a low power warning voltage value, detects a battery voltage of said at least one battery cell, generates a low power warning when the detected battery voltage is less than or equal to the corrected low power warning voltage value, generates a residual power indication when the detected battery voltage is greater than the corrected low power warning voltage value, and displays the low power warning or the residual power indication.

19. A battery pack as claimed in claim 18, wherein the correction value is a first value when the capacity value exceeds a first predetermined value that is the capacity value when said battery has a first known number of cell structures, the correction value is a second value when the capacity value does not exceed the first predetermined value but exceeds a second predetermined value that is the capacity value of when said battery has a second known number of cell structures, the first known number of cell structures being greater than the second known number of cell structures, and the correction value is zero when the capacity value does not exceed the second predetermined value.