Security device

• US 20080170287A1
• Filed: 01/12/2007
• Published: 07/17/2008
• Est. Priority Date: 01/12/2007
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Champion, David A., Betrabet, Chinmay Suresh
• Granted Patent: US 7,599,109 B2
• Time in Patent Office: Days
• US Class Current: 359/275
• CPC Class Codes: G02F 1/15 based on an electrochromic effect
• CPC Class Codes: G09F 3/0305 characterised by the type of seal used
• CPC Class Codes: G09F 3/0376 using a special technique to detect tampering, e.g. by ultrasonic or optical means

Abstract

Embodiments of a security device utilizing electrochromic material are disclosed.

Claims

1. A security device, comprising:

a first electrode member;

a second electrode member including a transparent security display region; and

an electrochromic material positioned between said first electrode member and said second electrode member in said transparent security display region.

2. The device of claim 1 wherein said electrochromic material is activated from an unactivated condition to an activated condition upon a change in potential applied between said first and second electrode members.

3. The device of claim 2 wherein said electrochromic material provides a visible security display in said security display region in said activated condition.

4. The device of claim 3 wherein said electrochromic material provides an absence of a visible security display in said security display region in said unactivated condition.

5. The device of claim 1 further comprising an adhesive positioned on said first electrode member to secure said security device to a secured article.

6. The device of claim 1 further comprising a potential source connected to said first and second electrodes that provides a change in potential to move said electrochromic material between said activated and unactivated conditions.

7. The device of claim 1 further comprising a control system that controls said potential source.

8. The device of claim 2 wherein said electrochromic material is activated to and remains in an activated condition for a first length of time when said change in potential applied is greater than a threshold level and wherein said electrochromic material is activated to and remains in an activated condition for a second length of time when said change in potential applied is less than a threshold level, wherein said first length of time is greater than said second length of time.

9. The device of claim 8 wherein said first length of time is at least twenty four hours and wherein said second length of time is less than ten minutes.

10. The device of claim 8 wherein said threshold level defines a potential that retains said electrochromic material in said activated condition for a temporary time period regardless of a potential applied to said electrochromic material during said temporary time period.

11. The device of claim 2 further comprising a timing device connected to said first and second electrodes, wherein said timing device controls activation of said electrochromic material such that said electrochromic material flashes a visible light in said activated condition when said timing device controls said first and second electrodes.

12. The device of claim 10 further comprising an erase device that activates said device to an irreversibly opaque condition when said timer circuit reaches the end of a timed period.

13. The device of claim 1 wherein said electrochromic material is dissolved in a solvent positioned between said first electrode member and said second electrode member in said transparent security display region.

14. The device of claim 7 wherein said control device is a radio frequency control device that allows control of said device from a location remote from the device.

16. The method of claim 14 wherein said step of generating a potential difference comprises generating a potential difference greater than a threshold value such that said electrochromic material is irreversibly moved to said activated condition during a predetermined time period.

17. The method of claim 14 wherein said step of generating a potential difference comprises generating a potential difference less than a threshold value such that said electrochromic material is moved to said activated condition only while said potential difference is being generated.

18. The method of claim 14 further comprising:

removing said potential difference;

said removing said potential difference moving said electrochromic material from said activated condition to said unactivated condition; and

wherein said electrochromic material in said unactivated condition generates an absence of a visible security indication through said transparent region of said second electrode.

19. The method of claim 14 further comprising generating an expiration potential difference between said first electrode and said second electrode that irreversibly moves said electrochromic material to an expiration condition.

21. The method of claim 19 further comprising connecting said first and said second electrodes to a potential source adapted for applying a potential difference between said first and said second electrodes to move said electrochromic material to a visible security alarm condition.

15. A method of using a security device, comprising:

generating a potential difference between a first electrode and a second electrode of a security device, said second electrode including a transparent region;

said potential difference moving an electrochromic material positioned between said first and second electrodes from an unactivated condition to an activated condition; and

said electrochromic material in said activated condition generating a visible security indication through said transparent region of said second electrode.

20. A method of making a security tag, comprising:

forming a layered structure including a first electrode, a second electrode, and an electrochromic material positioned between said first and second electrodes.