Electronic device with low battery warning

• US 8,284,302 B2
• Filed: 08/14/2006
• Issued: 10/09/2012
• 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, Ebato, Satoshi, Ieki, Shinji
• Primary Examiner(s): Moe, Aung S
• Assistant Examiner(s): YODER III, CHRISS S
• Application Number:
  US11/504,244
• Publication Number:
  US 20060274192A1
• Time in Patent Office: 2,248 Days
• Field of Search: 348/372, 348/333.02, 348/333.04, 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 video camera includes a processor that is operable to obtain a capacity value of a battery by communicating over a communications line with a battery pack that contains the battery and which provides power to the video camera. The capacity value indicates a number of cell structures in the battery. The processor is also operable to set a correction value based on the capacity value, to correct a low power warning voltage value by subtracting the correction value from the low power warning voltage value, to generate a low power warning when a detected battery voltage is less than or equal to the corrected low power warning voltage value, and to generate a residual power indication when the detected battery voltage is greater than the corrected low power warning voltage value. A display is operable to display the low power warning or the residual power indication.

Claims

1. A video camera, comprising:

a processor that obtains a capacity value of a battery by communicating over 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, determines a residual power amount of the battery based on the capacity value, sets a correction value based on the capacity value, determines a type of the battery pack based on the capacity value, stores in a memory the correction value in association with the type of the battery pack, corrects a low power warning voltage value by subtracting the correction value from the low power warning voltage value, generates a low power warning in response to a detected battery voltage being less than or equal to the corrected low power warning voltage value, and generates a display of the residual power amount in response to the detected battery voltage being greater than the corrected low power warning voltage value; and

a display that displays the low power warning or the residual power amount.

2. A video camera as claimed in claim 1, further comprising a detector section that detects the battery voltage.

3. A video camera as claimed in claim 1, further comprising said memory, said processor obtaining the capacity value from said memory.

4. A video camera as claimed in claim 1, wherein said processor generates the low power warning in response to the detected battery voltage being greater than a minimum operating voltage.

5. 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.

6. A video camera 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;

a processor that obtains a capacity value of said battery by communicating with said battery pack over said communications line, the capacity value indicating a number of cell structures in the battery, determines a residual power amount of the battery based on the capacity value, sets a correction value based on the capacity value, determines a type of the battery pack based on the capacity value, stores in a memory the correction value in association with the type of the battery pack, corrects a low power warning voltage value by subtracting the correction value from the low power warning voltage value, generates a low power warning in response to a detected battery voltage being less than or equal to the corrected low power warning voltage value, and generates a display of the residual power amount in response to the detected battery voltage being greater than the corrected low power warning voltage value, and

a display that displays the low power warning or the residual power amount.

7. A video camera system as claimed in claim 6, wherein said battery pack includes said memory, said processor of said video camera body obtaining the capacity value from said memory.

8. A video camera system as claimed in claim 6, wherein said video camera body includes a detector section operable detect the battery voltage.

9. A video camera system as claimed in claim 6, 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.

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

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

a power terminal that supplies power to a video camera body of the video system over a power source line;

a memory that stores a capacity value of said battery in association with a type of said battery pack, the capacity value indicating a number of battery cells in said battery, the type of the battery pack being based on the capacity value;

a communications terminal that provides a connection to a communications line connected between said battery pack and the video camera body; and

a processor that provides the capacity value stored in said memory to the video camera body using said communications terminal and the communications line;

said video camera body thereby determining a residual power amount of the battery based on the capacity value, setting a correction value based on the provided capacity value, correcting a low power warning voltage value by subtracting the correction value from a low power warning voltage value, detecting a battery voltage of said at least one battery cell, generating a low power warning in response to the detected battery voltage being less than or equal to the corrected low power warning voltage value, generating a display of the residual power amount in response to the detected battery voltage being greater than the corrected low power warning voltage value, and displaying the low power warning or the residual power amount.

11. A battery pack as claimed in claim 10, 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.