System and method for managing utilization of a battery

• US 5,963,255 A
• Filed: 04/16/1996
• Issued: 10/05/1999
• Est. Priority Date: 04/16/1996
• Status: Expired due to Term

• Current Assignee: Apple Computer Incorporated (Apple Inc.)
• Original Assignee: Apple Computer Incorporated (Apple Inc.)
• Inventors: Anderson, Eric C., Fullam, Scott F.
• Primary Examiner(s): HO, TUAN V
• Application Number:
  US08/633,105
• Time in Patent Office: 1,267 Days
• Field of Search: 320/127, 320/128, 320/129, 320/130, 320/131, 320/132, 320/133, 320/135, 320/136, 320/207, 455/343, 455/574, 348/372, 348/207
• US Class Current: 348/372
• CPC Class Codes: H04N 23/651 for reducing power consumption by affecting camera operations, e.g. sleep mode, hibernation mode or power off of selective parts of the camera

Abstract

A power supply provides a voltage to a digital camera. If the power supply voltage falls below a predetermined threshold, a voltage sensor generates a signal to a power manager. In response, the power manager configures the camera into a lower power consumption state. As the power source weakens further, the power manager continues to place the camera into a lower and lower power consumption state, until the power source is exhausted. The method of the present invention preferably comprises the steps of monitoring the power source'"'"'s voltage, generating a signal if that voltage falls below a pre-determined threshold, and reducing the camera'"'"'s power consumption in response to the signal.

Claims

1. A system for managing utilization of a power source within an electronic device having a set of power consumption states, comprising:

a voltage sensor for generating a signal if the power source'"'"'s voltage falls below a threshold voltage when the electronic device is in a first power state; and

a power manager coupled to the voltage sensor for placing the electronic device into a second power state in response to the signal;

a first subsystem configurable to consume one from a group consisting of a maximum power, a reduced power and no power; and

a second subsystem configurable to consume one from a group consisting of a maximum power and no power;

wherein the electronic device in the second power state consumes a different amount of power than when in the first power state;

wherein the first power state configures the electronic device for full power operation, and the second power state configures the electronic device for reduced power operation;

wherein the power manager places the electronic device into a third power state in response to a second signal from the voltage sensor, and the third power state configures the electronic device to consume less power than in the second power state;

wherein in the first power state the first subsystem and the second subsystem are configured to consume maximum power;

wherein in the second power state the first subsystem is configured to consume reduced power and the second subsystem is configured to consume maximum power;

wherein in the third power state the first subsystem is configured to consume no power and the second subsystem is configured to consume maximum power;

wherein the power manager places the electronic device into a fourth power state in response to a third signal from the voltage sensor; and

wherein in the fourth power state the first subsystem is configured to consume no power and the second subsystem is configured to consume no power.

2. The system of claim 1, wherein:

the electronic device is a camera;

the first subsystem is a flash unit; and

the second subsystem is comprised of capture electronics and motors.

3. The system of claim 1, wherein the power source comprises a battery.

4. The system of claim 3, wherein the battery is an alkaline battery.

5. A system for managing utilization of a power source within an electronic device having a set of power consumption states, comprising:

a voltage sensor for generating a signal if the power source'"'"'s voltage falls below a threshold voltage when the electronic device is in a first power state; and

a power manager coupled to the voltage sensor for placing the electronic device into a second power state in response to the signal;

a flash unit configurable to consume one from a group consisting of a maximum power, a reduced power and no power; and

a set of motors configurable to consume one from a group consisting of a maximum power and no power;

wherein the electronic device in the second power state consumes a different amount of power than when in the first power state;

wherein the first power state configures the electronic device for full power operation and the second power state configures the electronic device for reduced power operation;

wherein the power manager places the electronic device into a third power state in response to a second signal from the voltage sensor and the third power state configures the electronic device to consume less power than in the second power state;

wherein in the first power state the flash unit and the set of motors are configured to consume maximum power;

wherein in the second power state the flash unit is configured to consume reduced power and the set of motors is permitted to operate in parallel; and

wherein in the third power state the flash unit is configured to consume no power and the set of motors is configured to operate sequentially.

6. A method for managing utilization of a power source within a camera having a flash unit and a set of motors and having a power consumption, the method comprising the steps of:

monitoring a voltage of the power source;

determining if the voltage has fallen below a threshold voltage and, if it has, then reducing the power consumption of the camera and configuring the camera into a mid-level power state and configuring the flash unit to operate at reduced power; and

configuring the camera into a low-level power state and disabling the flash unit and permitting only the sequential operation of the set of motors if the voltage falls below the threshold voltage while the camera is in the mid-level power state;

waiting a predefined amount of time, after performing the reducing step;

returning to the monitoring step, if the voltage has risen above the threshold voltage;

executing a power failure shut-down sequence, if the voltage has not risen above the threshold voltage; and

initializing the camera into a high-level power state and configuring the flash unit to operate at maximum power.

7. An apparatus for managing utilization of a power source within a camera having a flash unit, a set of motors and a power consumption, comprising:

means for monitoring a voltage of the power source;

means for reducing the power consumption of the camera if the voltage falls below a threshold voltage, including;

means for configuring the camera into a mid-level power state and for permitting the flash unit to operate at reduced power if the voltage falls below the threshold voltage; and

means for configuring the camera into a low-level power state and for disabling the flash unit and permitting only the sequential operation of the set of motors, if the voltage falls below the threshold voltage while the camera is in the mid-level power state;

means for determining if the voltage has fallen below the threshold voltage, before performing the means for reducing;

means for waiting a predefined amount of time, after performing the means for reducing;

means for returning to the means for monitoring, if the voltage has risen above the threshold voltage;

means for executing a power failure shut-down sequence, if the voltage has not risen above the threshold voltage;

means for initializing the camera into a high-level power state and for permitting the flash unit to operate at maximum power.