Portable device with freefall detection or audio processing subsystem and freefall detection or audio processing method
First Claim
1. A method for determining that a disk device is in freefall, including the steps of:
- (a) determining from acceleration data indicative of instantaneous acceleration of the disk device whether said instantaneous acceleration is less than gravitational acceleration during a first time interval of predetermined duration;
(b) determining from the acceleration data whether said instantaneous acceleration has a time derivative whose absolute magnitude exceeds a predetermined minimum value during a second time interval having a second predetermined duration; and
(c) determining that the disk device is in freefall by determining that said instantaneous acceleration is not less than gravitational acceleration during the first time interval and the absolute magnitude of the time derivative of said instantaneous acceleration does not exceed the predetermined minimum value during the second time interval.
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Accused Products
Abstract
In a class of embodiments, a method and apparatus for detecting freefall of a disk device (thereby predicting that the disk device will likely suffer imminent physical impact) and typically also preventing damage that a disk drive of the device would otherwise suffer if and when a predicted impact occurs. In some embodiments, a disk device includes a freefall detection processor and a CPU. The freefall detection processor is configured to monitor acceleration data to determine whether the disk device is in freefall and to perform at least one other operation (e.g., decoding of MP3-encoded audio data to generate decoded audio data) while the CPU performs at least one other task. Other embodiments pertain to a portable device including a digital audio processing subsystem and an accelerometer. The digital audio processing subsystem is configured to monitor acceleration data to identify any rhythm associated with motion of the portable device and to modify the playback of audio data in response to any such identified rhythm.
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Citations
31 Claims
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1. A method for determining that a disk device is in freefall, including the steps of:
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(a) determining from acceleration data indicative of instantaneous acceleration of the disk device whether said instantaneous acceleration is less than gravitational acceleration during a first time interval of predetermined duration;
(b) determining from the acceleration data whether said instantaneous acceleration has a time derivative whose absolute magnitude exceeds a predetermined minimum value during a second time interval having a second predetermined duration; and
(c) determining that the disk device is in freefall by determining that said instantaneous acceleration is not less than gravitational acceleration during the first time interval and the absolute magnitude of the time derivative of said instantaneous acceleration does not exceed the predetermined minimum value during the second time interval. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A disk device having a freefall detection subsystem configured to detect freefall of the disk device, said freefall detection subsystem including:
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an accelerometer; and
a freefall detection processor coupled and configured to perform freefall detection by monitoring acceleration data indicative of acceleration of the disk device sensed by the accelerometer and determining in response to the acceleration data whether the disk device is in freefall, wherein the freefall detection processor is also configured to at least one other operation. - View Dependent Claims (12, 13)
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14. A disk device having a freefall detection subsystem configured to detect freefall of the disk device, said freefall detection subsystem including:
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an accelerometer; and
a freefall detection processor coupled and configured to perform freefall detection by monitoring data indicative of instantaneous acceleration of the disk device as sensed by the accelerometer and determining in response to the data whether the disk device is in freefall, including by (a) determining from the data whether said instantaneous acceleration is less than gravitational acceleration during a first time interval of predetermined duration, (b) determining from the data whether said instantaneous acceleration has a time derivative whose absolute magnitude exceeds a predetermined minimum value during a second time interval having a second predetermined duration; and
(c) determining that the disk device is in freefall by determining that said instantaneous acceleration is not less than gravitational acceleration during the first time interval and the absolute magnitude of the time derivative of said instantaneous acceleration does not exceed the predetermined minimum value during the second time interval. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A portable device, including:
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an accelerometer; and
a digital audio processing subsystem, coupled and configured to process digital audio data for playback, and to monitor data indicative of instantaneous acceleration of the portable device as sensed by the accelerometer to identify a rhythm associated with motion of the portable device. - View Dependent Claims (26, 27, 28)
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29. A method for operating a portable device that includes at least one accelerometer, said method including the steps of:
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(a) processing digital audio data for playback; and
(b) identifying a rhythm associated with motion of the device by processing acceleration data indicative of instantaneous acceleration of the device as sensed by the accelerometer. - View Dependent Claims (30, 31)
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Specification