Anti-theft alarm for portable electrically operated devices

• US 6,072,393 A
• Filed: 12/18/1998
• Issued: 06/06/2000
• Est. Priority Date: 12/19/1997
• Status: Expired due to Fees

• Current Assignee: Micro Snitch Corporation
• Original Assignee: Micro Snitch Corporation
• Inventors: Todd, John M.
• Primary Examiner(s): Lee, Benjamin C.
• Application Number:
  US09/215,230
• Time in Patent Office: 536 Days
• Field of Search: 340/571, 340/568.2, 340/572.1, 340/686.1, 340/868.1, 70/57.1
• US Class Current: 340/568.2
• CPC Class Codes: G06F 21/88 Detecting or preventing theft or loss
• CPC Class Codes: G08B 13/1409 for removal detection of electrical appliances by detecting their physical disconnection from an electrical system, e.g. using a switch incorporated in the plug connector

Abstract

An anti-theft alarm is provided, for a portable device such as a laptop computer. An embodiment of the anti-theft alarm comprises three main components: a uniquely coded tag for attachment to the bottom of the device, a pad upon which the device is placed, for sensing the tag, and an electrically powered control module. The module is connected to the pad. The control module is able to determine if the tag is still in contact with the pad--if not an alarm sounds immediately. The module can also determine if the electrical power has been disconnected and if the module has been moved (using a motion sensor). If there is no power and the module has been moved, an alarm sounds immediately. The alarm can be disabled with a key switch.

Claims

1. An anti-theft alarm for a device having an underside, said anti-theft alarm comprising:

a) an electronically coded tag for attachment to the underside of the device,

b) a sensing means for placement adjacent to the coded tag and for sensing the code on the tag,

c) an electrically operated control module connectable to the sensing means and to an electrical power supply,

said control module having i) a recognition sensor for recognizing a predetermined code on the coded tag, ii) a motion detector, iii) a tamper sensor for determining a condition selected from the group consisting of a first condition which consists of lack of recognition of the coded tag and a second condition which consists of disconnection of the electrical power together with movement of the control module as detected by the motion sensor, iv) an alarm which is initiated by the tamper sensor under conditions of the first or second conditions, and an arming latch to keep the alarm activated while the first or second condition persists, and v) deactivation means for deactivating the alarm or the tamper sensor.

2. An anti-theft alarm for device, said anti-theft alarm comprising:

a) a first uniquely coded security element for attachment to the device,

b) a second security element for cooperating with said first security element,

c) an electrically operated control module connectable to the second security element and to an electrical power supply, said control module having i) a recognition sensor for recognizing cooperation of the first and second security elements, ii) a motion detector, iii) a tamper sensor for determining a condition selected from the group consisting of a first condition which consists of lack of recognition of the cooperation of the first and second security elements and a second condition which consists of disconnection of the electrical power together with movement of the control module as detected by the motion sensor, iv) an alarm which is initiated by the tamper sensor under conditions of the first or second conditions, and an arming latch to keep the alarm activated while the first or second condition persists, and v) deactivation means for deactivating the alarm or the tamper sensor.