Automotive radio anti-theft device via multiplex bus
First Claim
1. An anti-theft device for an automobile audio system which automatically prevents the audio system from functioning whenever the audio system is removed from its authorized vehicle and placed into another vehicle, comprising:
- the audio system having a central microprocessor, a battery detector, a bus interface, a non-volatile memory and a second memory;
the battery detector connected to the central microprocessor, said battery detector alerting the central microprocessor whenever the audio system has been disconnected from a battery;
the bus interface connected to the central microprocessor and a vehicle communication bus for communicating a first authorized vehicle identifier and a next subsequent vehicle identifier received via the vehicle communication bus from a source in the authorized vehicle and from a source in any vehicle, respectively to said central microprocessor, each said first authorized vehicle identifier and said next subsequent vehicle identifier being pre-stored in said source in the authorized vehicle and in said source in any vehicle, respectively;
the first authorized vehicle identifier is recieved and stored in said non-volatile memory by said microprocessor only when initializing the anti-theft device;
whenever the battery detector determines that the audio system has been disconnected from the battery and reconnected, said next subsequent vehicle identifier is automatically recieved and stored in said second memory by said microprocessor, and thensaid microprocessor automatically compares the first authorized vehicle identifier stored within the non-volatile memory to the next subsequent vehicle identifier stored in said second memory, and shuts down the audio system whenever the first authorized and the next subsequent vehicle identifiers do not match.
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Accused Products
Abstract
An anti-theft device for an automobile audio system automatically prevents the audio system from functioning whenever the audio system is removed from its authorized vehicle and placed into another vehicle. This anti-theft device includes a microprocessor which operates with a bus interface for communicating a vehicle identifier from a vehicle multiplex bus to the central microprocessor. The device also has non-volatile memory within which the first received or authorized vehicle identifier is stored. The subsequently received identifiers are stored on RAM. A battery detector connected to the microprocessor alerts the microprocessor whenever the audio system has been disconnected from the battery source. When the audio system is reconnected to the battery source, the microprocessor automatically compares the vehicle identifier stored within the non-volatile memory to the subsequent vehicle identifier received in the RAM over the multiplex bus, and shuts down the audio system whenever these two vehicle identifiers do not match.
63 Citations
25 Claims
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1. An anti-theft device for an automobile audio system which automatically prevents the audio system from functioning whenever the audio system is removed from its authorized vehicle and placed into another vehicle, comprising:
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the audio system having a central microprocessor, a battery detector, a bus interface, a non-volatile memory and a second memory; the battery detector connected to the central microprocessor, said battery detector alerting the central microprocessor whenever the audio system has been disconnected from a battery; the bus interface connected to the central microprocessor and a vehicle communication bus for communicating a first authorized vehicle identifier and a next subsequent vehicle identifier received via the vehicle communication bus from a source in the authorized vehicle and from a source in any vehicle, respectively to said central microprocessor, each said first authorized vehicle identifier and said next subsequent vehicle identifier being pre-stored in said source in the authorized vehicle and in said source in any vehicle, respectively; the first authorized vehicle identifier is recieved and stored in said non-volatile memory by said microprocessor only when initializing the anti-theft device; whenever the battery detector determines that the audio system has been disconnected from the battery and reconnected, said next subsequent vehicle identifier is automatically recieved and stored in said second memory by said microprocessor, and then said microprocessor automatically compares the first authorized vehicle identifier stored within the non-volatile memory to the next subsequent vehicle identifier stored in said second memory, and shuts down the audio system whenever the first authorized and the next subsequent vehicle identifiers do not match. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method for initializing an anti-theft device installed within an automobile audio system, comprising the steps of:
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automatically transmitting over a vehicle communication bus to which the audio system is coupled a vehicle identifier to a microprocessor located within the audio system from a source in a vehicle in which the vehicle identifier is pre-stored; confirming that the vehicle identifier is in fact valid; and storing the vehicle identifier in a memory location within the anti-theft device, wherein the vehicle identifier is a unique vehicle identification number; wherein the step of confirming that the vehicle identification number is in fact valid further comprises the steps of; classifying one digit of the vehicle identification number as a check digit; automatically calculating a check value by using each digit within the unique vehicle identification number; assigning the check value to the check digit, and storing the check value within the anti-theft device. - View Dependent Claims (15)
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16. A method for performing a security check using an anti-theft device installed within an automobile audio system, comprising the steps of:
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confirming that the anti-theft device has previously been initialized by checking to see whether a first vehicle identifier has been stored within the anti-theft device; automatically receiving a second vehicle identifier from a vehicle multiplex bus, on which it has been transmitted from a source in a vehicle in which the second vehicle identifier has been pre-stored, at least as often as every time the ignition is turned on; continuously comparing the second vehicle identifier to the first vehicle identifier, to ensure that the first and second vehicle identifiers match; and shutting down the audio system whenever a discrepancy between the first and second vehicle identifiers is detected. - View Dependent Claims (17, 18, 19, 20, 21, 22)
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23. A method for performing a security check using an anti-theft device installed within an automobile audio system, comprising the steps of:
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confirming that the anti-theft device has previously been initialized by checking to see whether a first vehicle identifier has been stored within the anti-theft device; alerting a user that the anti-theft device is performing its security check; automatically receiving a second vehicle identifier from a vehicle multiplex bus, on which it has been transmitted from a source in a vehicle in which the second vehicle identifier has been pre-stored, at least as often as every time the ignition is turned on; comparing the second vehicle identifier to the first vehicle identifier, to ensure that the first and second vehicle identifiers match; and shutting down the audio system whenever a discrepancy between the first and second vehicle identifiers is detected. - View Dependent Claims (24, 25)
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Specification