Burglarproof device
First Claim
1. A theft prevention device comprising an optical sensor for detecting a level of ambient light, a vibration sensor for detecting vibration of a protected article, and an alarm circuit operatively coupled to the optical sensor and the vibration sensor for providing an alarm when the optical sensor detects a change in the level of ambient light from relative brightness to relative darkness and the vibration sensor detects a vibration of the protected article.
2 Assignments
0 Petitions
Accused Products
Abstract
A theft prevention device includes an optical sensor for detecting a level of ambient light and a vibration sensor for detecting a vibration of a protected article. The theft prevention device further includes an alarm circuit operatively coupled to the optical sensor and the vibration sensor for providing an alarm when the optical sensor detects a change in the level of ambient light from relative brightness to relative darkness and the vibration sensor detects a vibration of the protected article. The theft prevention device may further include a disconnection sensor for detecting a disconnection of a member attached to the protected article, whereby the alarm circuit activates the alarm upon such disconnection. The theft prevention device may further include a microswitch which is automatically activated upon removal of the protected article from an article casing. Still furthermore, the theft prevention device may include devices located at an exit of a place in which the protected article is located for emitting a high frequency light which may be detected by the optical sensor.
73 Citations
26 Claims
- 1. A theft prevention device comprising an optical sensor for detecting a level of ambient light, a vibration sensor for detecting vibration of a protected article, and an alarm circuit operatively coupled to the optical sensor and the vibration sensor for providing an alarm when the optical sensor detects a change in the level of ambient light from relative brightness to relative darkness and the vibration sensor detects a vibration of the protected article.
- 6. A theft prevention device comprising an optical sensor for detecting a level of ambient light, a vibration sensor for detecting vibration of a protected article, a disconnection sensor for detecting a disconnection of a member attached to the protected article, and an alarm circuit operatively coupled to the optical sensor, the vibration sensor and the disconnection sensor for providing an alarm when the optical sensor detects a change in the level of the ambient light from relative brightness to relative darkness and the vibration sensor detects a vibration of the protected article, or when the disconnection sensor detects a disconnection of the member.
- 9. A theft prevention device comprising an optical sensor for detecting a level of ambient light, a vibration sensor for detecting vibration of a protected article, and an alarm circuit operatively coupled to the optical sensor and the vibration sensor for providing an alarm when the optical sensor detects a change in the level of the ambient light from relative brightness to relative darkness and the vibration sensor detects a vibration of the protected article, the vibration sensor being composed of a body movable in response to vibration of the vibration sensor and a detecting body for detecting a movement of the movable body.
- 18. A theft prevention device comprising an optical sensor for detecting a level of ambient light and for converting the detected light level to a first electric signal, a vibration sensor for detecting a vibration of a protected article and for converting the detected vibration to a second electric signal, and an alarm circuit for receiving the first electric signal provided by the optical sensor and the second electric signal provided by the vibration sensor and for providing an alarm when the first electric signal provided by the optical sensor exceeds a predetermined frequency at a time when a vibration of the protected article is detected by the vibration sensor.
- 21. A theft prevention device comprising an optoelectronic element for generating an optoelectronic voltage responsive to the incidence of light, an optical processing circuit for receiving the optoelectronic voltage generated by the optoelectronic element for charging a cell for supplying power to constituents of the device, a vibration sensor for detecting vibration of a protected article, and an alarm circuit operatively coupled to the vibration sensor and the optoelectronic element for providing an alarm when the optoelectronic element detects a change in a level of the light from relative brightness to relative darkness and the vibration sensor detects vibration of the protected article.
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23. A theft prevention device comprising an optoelectronic element for generating an optoelectronic voltage responsive to the incidence of light, an optical processing circuit for receiving the optoelectronic voltage generated by the optoelectronic element and for providing a first detecting signal, a vibration sensor for detecting vibration of a protected article and for providing a second detection signal indicative of the vibration, and an alarm circuit for receiving the second detections signal provided by the vibration sensor and the first detection signal provided by the optical processing circuit for providing an alarm when the first detection signal provided by the optical processing circuit indicates a change in a level of the light from relative brightness to relative darkness at a time when the vibration sensor detects vibration of the protected article.
- 24. A theft prevention device comprising an optical sensor for detecting a level of ambient light, a vibration sensor composed of a molded body and a Hall-effect element and a ball respectively housed therein for detecting vibration of a protected article, and an alarm circuit operatively coupled to the optical sensor and the vibration sensor for providing an alarm when the optical sensor detects a change in the level of the ambient light from relative brightness to relative darkness and the vibration sensor detects vibration of the protected article, wherein the ball is made of a magnetic material and is movably disposed adjacent a detecting surface of the Hall-effect element.
Specification