Security system with automatic door locking/unlocking function

• US 5,969,596 A
• Filed: 05/27/1998
• Issued: 10/19/1999
• Est. Priority Date: 05/27/1998
• Status: Expired due to Fees

• Current Assignee: Multistar Industries Co., Ltd.
• Original Assignee: Multistar Industries Co., Ltd.
• Inventors: Wu, Jun-Nan
• Primary Examiner(s): Crosland, Donnie L.
• Application Number:
  US09/085,596
• Time in Patent Office: 510 Days
• Field of Search: 340/426, 340/425.5, 340/825.69, 340/825.72
• US Class Current: 340/426.17
• CPC Class Codes: B60R 25/1001 Alarm systems associated with another car fitting or mechanism, e.g. door lock or knob, pedals features related to the general power supply B60R25/1018
• CPC Class Codes: G07C 2009/00769 with data transmission performed by wireless means
• CPC Class Codes: G07C 9/00182 operated with unidirectional data transmission between data carrier and locks

Abstract

A car security alarm system includes a receiver portion incorporated in a car electricity system and in electrical/mechanical connection with associated parts/systems of the car and a transmitter portion to be carried by a driver of the car. The transmitter portion repeatedly emits a predetermined signal including an identification code at predetermined intervals. The receiver portion includes a receiving circuit to receive the signal and an identifying circuit to determine if the identification code is correct and apply a confirmation signal to a central processing unit in case the identification code is correct and the central processing unit generates an instruction to unlock the car door in the situation that the car security alarm system is in activated condition. In the condition that the system is in de-activated condition, if no such identification signal is detected by the receiver portion within a predetermined period, then the central processing unit generates a signal to lock the car door.

Claims

1. A car security alarm system comprising:

a transmitter portion to be carried by a car driver, the transmitter portion comprising a signal generation circuit which generates an encoded signal comprising an identification code and a transmitting circuit which automatically and repeatedly emits the encoded signal at predetermined intervals; and

a receiver portion adapted to be incorporated in a car having a door and an electrical system, the receiver portion comprising;

a receiving circuit for receiving the encoded signal from the transmitter portion;

an amplifier circuit connected to the receiving circuit for amplifying the signal received by the receiving circuit;

a decoder circuit connected to the amplifier circuit for decoding the signal received by the receiving circuit and amplified by the amplifier circuit to obtain the identification code carried by the received signal;

storage means storing therein at least one set of data for confirming the identification code carried by the received signal;

an identifying circuit which receives the decoded signal from the decoder circuit and accesses the data stored in the storage means to confirm the identification code of the received signal and generates a confirmation signal;

a central processing unit which receives the confirmation signal from the identification circuit to provide a driving signal and a control signal;

a driving circuit which is coupled to the car electrical system, the driving circuit receiving the driving signal from the central processing unit to lock/unlock the car door; and

an alarm generation circuit which is coupled to the central processing unit to receive the control signal therefrom for activating/de-activating the alarm generation circuit to generate an alarm signal,

wherein when the car security alarm system is in an activated condition, the receiver portion, upon receiving the encoded signal from the transmitter portion deactivates the car security alarm system and unlocks the car door, and when the car security alarm system is in de-activated condition, the receiver portion, upon detecting no such encoded signal from the transmitter portion, activates the car security alarm system and locks the car door.

2. The car security alarm system as claimed in claim 1, wherein the storage means has a plurality of sets of data stored therein to confirm the identification code of the received signal.

3. The car security alarm system as claimed in claim 1, wherein the receiver portion further comprises a timer circuit for setting a predetermined time period for activating the car security alarm system.