US 6,050,622 · Granted 2000-04-18
The Electronic Tamper-Proof Seal That Knows When You've Opened It
Imagine a sticker that can detect if someone has tried to peel it off. This invention combines a tiny electronic chip with a fine wire antenna glued to a support—when someone tries to remove the seal or tear it, the wire breaks, and the chip stops responding, proving the seal has been messed with.
The plain-English version
What it protects
The claim covers a physical safety seal made of a support material with an electronic circuit glued to it, where a fine wire wound as part of the circuit acts as an antenna. What's protected here is the specific way the electronic component responds to outside interrogation signals through that wire antenna, and how breaking or ungluing the seal causes the circuit to fail—making tampering detectable. The protection extends to the coded response system, where the electronic component broadcasts a unique code when queried, and that code stops being transmitted once the seal is compromised.
Why it matters
This patent addresses a real security problem: how to create a seal that passively proves it hasn't been tampered with, without batteries or active power. By combining a simple wire antenna with a passive electronic component, the design allows tamper detection through non-contact interrogation—meaning a checker can verify a seal's integrity by scanning it without opening or destroying it. This is valuable for shipping, pharmaceuticals, or any high-security packaging where proof of integrity matters more than preventing access.
Real-world use
You'd encounter this in high-value shipments, pharmaceutical packaging, or secure documents where a scanner can wirelessly check whether the seal has been disturbed since it was applied, giving instant confirmation of whether something's been opened.
Original USPTO abstract
A safety sealing device includes a support. An electronic safety circuit is glued to one face of the support. The electronic safety circuit includes a winding of fine wire connected to an electronic component. The electronic component is activated and interrogated by outside checking means via the winding, which acts as an antenna. The electronic component may be coded so that it responds to the interrogation with its code. The safety sealing device may further comprise differentiated gluing means. When attempting to tamper with the support to which the safety circuit has been glued in order to unseal a receiving article, the attempt at ungluing or a tearing causes a break in the continuity of the electronic circuit. As a result, the electronic component no longer responds to an interrogation with its code, thus assuredly indicating that the safety sealing device has been tampered with.
Patent details
- Publication number
- US 6,050,622
- Filing date
- 1996-12-24
- Grant date
- 2000-04-18
- Assignee
- Gustafson; Ake
- Inventor(s)
- GUSTAFSON; AKE
- CPC class
- G09F3/0341
Want to file your own patent?
If you're thinking about designing a security product for home or building applications, search our patent database to see what tamper-detection innovations already exist in your space.
Free patentability scan