Capacitive method and apparatus for accessing contents of envelopes and other similarly concealed information

• US 6,168,080 B1
• Filed: 04/14/1998
• Issued: 01/02/2001
• Est. Priority Date: 04/17/1997
• Status: Expired due to Fees

• Current Assignee: Translucent Technologies, LLC
• Original Assignee: Translucent Technologies, LLC
• Inventors: Leordeanu, Corneliu C., Mitchell, Chauncey T. Jr., Verschuur, Gerrit L.
• Primary Examiner(s): Hajer, Donald
• Assistant Examiner(s): Felten, Daniel S
• Application Number:
  US09/059,985
• Time in Patent Office: 994 Days
• Field of Search: 235/61.11, 235/61.12, 235/487, 235/491, 235/493, 235/462.01, 235/492, 235/451
• US Class Current: 235/462.01
• CPC Class Codes: B07C 1/00 Measures preceding sorting according to destination
• CPC Class Codes: B07C 3/12 using electric or electronic detecting means B07C3/14 takes precedence
• CPC Class Codes: G06K 19/067 Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components
• CPC Class Codes: G06K 7/081 electrostatic, e.g. by detecting the charge of capacitance between electrodes

Abstract

The contents of sealed envelopes are accessed by detecting and digitizing a change in capacitance produced when a pattern of dielectric or conductive ink is passed by a sensitive capacitance sensor. The capacitance changes are converted into corresponding electrical patterns for further processing.

Claims

1. A method of reading information encoded on a substrate behind a cover in a pattern using an electrically conducting ink comprising the steps of:

relatively moving the encoded substrate and cover past a capacitance sensor in a fashion that permits different portions of the pattern to be measured at points of approximately equal proximity to the capacitance sensor;

successively measuring the different portions of the pattern as the encoded substrate is relatively moved past the capacitance sensor;

detecting variations in capacitance associated with the pattern of the conductive ink as a function of a relative position of the capacitance sensor along the covered substrate; and

matching the detected variations in capacitance to stored information about similar patterns for reading the encoded information.

2. The method of claim 1 in which the encoded information is printed in the form of a bar-code.

3. The method of claim 1 in which the electrically conductive ink is invisible.

4. The method of claim 1 in which the capacitance sensor includes side-by-side plates and including the further step of orienting the side-by-side plates adjacent to a common side of the substrate.

5. The method of claim 1 in which the substrate is substantially composed of a dielectric material.

6. The method of claim 1 in which the substrate has a plane surface, and the encoded information is printed entirely on the plane surface.

8. The method of claim 1 in which said step of detecting variations in capacitance includes detecting consequences of a change of impedance in a resonant circuit produced by the variations in capacitance.

7. A method of reading information encoded on a substrate behind a cover in a pattern using an electrically conducting ink comprising the steps of:

relatively moving the encoded substrate and cover past a capacitance sensor in a fashion that permits different portions of the pattern to be measured at points of approximately equal proximity to the capacitance sensor;

successively measuring the different portions of the pattern as the encoded substrate is relatively moved past the capacitance sensor;

detecting variations in capacitance associated with the pattern of the conductive ink as a function of a relative position of the capacitance sensor along the covered substrate; and

matching the detected variations in capacitance to stored information about similar patterns for reading the encoded information;

wherein the encoded information is printed on the substrate in patterns that represent alphanumeric characters.

9. A method of processing a succession of envelopes having processing information encoded in their contents comprising the steps of:

transporting the succession of envelopes together with their encoded contents past a capacitance sensor;

measuring variations in capacitance associated with patterns of the processing information recorded as a contrast in permittivity between the patterns and an underlying substrate;

deciphering the patterns into recognized units of information; and

distinguishing subsequent processing among envelopes on the basis of the processing information obtained from their contents;

wherein the patterns of the processing information are recorded in electrically conductive ink.

16. The method of claim 9 including the further step of printing the processing information on the substrate in a pattern using the electrically conductive ink.

17. The method of claim 9 in which the patterns of processing information recorded are recorded in a bar-code.

10. A method of processing a succession of envelopes having processing information encoded in their contents comprising the steps of:

transporting the succession of envelopes together with their encoded contents past a capacitance sensor;

measuring variations in capacitance associated with patterns of the processing information recorded as a contrast in permittivity between the patterns and an underlying substrate;

deciphering the patterns into recognized units of information; and

distinguishing subsequent processing among envelopes on the basis of the processing information obtained from their contents;

wherein said step of distinguishing includes sorting the envelopes in accordance with the processing information obtained from their contents.

11. A method of processing a succession of envelopes having processing information encoded in their contents comprising the steps of:

transporting the succession of envelopes together with their encoded contents past a capacitance sensor;

measuring variations in capacitance associated with patterns of the processing information recorded as a contrast in permittivity between the patterns and an underlying substrate;

deciphering the patterns into recognized units of information; and

distinguishing subsequent processing among envelopes on the basis of the processing information obtained from their contents;

wherein said processing information identifies intended addressees of the envelopes.

12. The method of claim 11 comprising the further steps of reading address information printed on an exterior of the envelopes and comparing the address information from the envelopes with the intended addressees obtained from their contents to determine if they match.

13. The method of claim 12 in which said step of distinguishing includes interrupting further processing of the envelopes upon detection of a mismatch between the address information from the envelopes and the intended addressees obtained from their contents.

14. The method of claim 11 in which said step of distinguishing includes printing address information on exteriors of the envelopes corresponding to the intended addressees obtained from their contents.

15. A method of processing a succession of envelopes having processing information encoded in their contents comprising the steps of:

transporting the succession of envelopes together with their encoded contents past a capacitance sensor;

measuring variations in capacitance associated with patterns of the processing information recorded as a contrast in permittivity between the patterns and an underlying substrate;

deciphering the patterns into recognized units of information; and

distinguishing subsequent processing among envelopes on the basis of the processing information obtained from their contents;

wherein said step of distinguishing includes generating a reply in accordance with the processing information obtained from the envelopes'"'"' contents.

18. A method of processing a succession of envelopes having processing information encoded in their contents comprising the steps of:

transporting the succession of envelopes together with their encoded contents past a capacitance sensor;

measuring variations in capacitance associated with patterns of the processing information recorded as a contrast in permittivity between the patterns and an underlying substrate;

deciphering the patterns into recognized units of information; and

distinguishing subsequent processing among envelopes on the basis of the processing information obtained from their contents;

wherein said step of deciphering includes converting the patterns of processing information into equivalent alphanumeric characters.

19. A system for assessing and processing encoded information printed on a succession of substrates with a conductive ink in patterns representing the encoded information comprising:

a transporter that conveys the succession of substrates printed with conductive ink in patterns representing encoded information;

a capacitance measuring device through which said succession of substrates is transported being sensitive to variations in capacitance associated with the patterns of the conductive ink as a function of a transported position of the substrates through the capacitance measuring device; and

a processor that evaluates the measured variations in capacitance for reading the encoded information.

25. The system of claim 19 in which the capacitance measuring device includes a pair of plates located adjacent to one side of the substrates.

26. The system of claim 25 in which said plates are arranged in parallel and oriented normal to a direction at which the substrates are transported past said plates.

27. The system of claim 25 in which said plates are aligned end-to-end and oriented normal to a direction at which the substrates are transported past said plates.

28. The system of claim 25 in which said encoded information is printed in the form of a bar-code, and said plates are aligned with the bar-code.

29. The system of-claim 28 in which capacitance is detected through an impedance change produced in a sensing circuit of the capacitance measuring device.

30. The system of claim 19 in which the conductive ink is printed on the substrates in a bar-code pattern.

31. The system of claim 30 in which said processor matches the measured variations in capacitance with known bar-code patterns to read the encoded information.

32. The system of claim 19 further comprising a sorter that distinguishes subsequent processing of the substrates based on the encoded information printed on the substrates.

33. The system of claim 19 in which the conductive ink is invisible.

34. The system of claim 19 further comprising covers that overlay the patterns of conductive ink on the substrates.

35. The system of claim 34 in which the covers obscure the patterns of conductive ink.

20. A system for assessing and processing hidden information imprinted on a succession of covered substrates comprising:

a transporter that conveys a succession of covered substrates imprinted with conductive ink in patterns representing encoded information visibly obscured by a cover;

a capacitance measuring device through which said succession of covered substrates are transported being sensitive to variations in capacitance associated with the patterns of the conductive ink as a function of a transported position of the covered substrates through the capacitance measuring device;

a processor that matches the measured variations in capacitance to stored information about similar patterns for reading the encoded information; and

a sorter that distinguishes subsequent processing of the covered substrates based on the encoded information imprinted on the substrates and obscured by the cover;

wherein said substrates include inserts printed with the conductive ink and mounted inside envelopes.

21. The system of claim 20 further comprising an optical reader for reading information printed on an outside of said envelopes.

22. The system of claim 21 in which said processor compares information read from the outside of the envelopes with the encoded information read from the inserts and controls a subsequent operation based on results of the comparison.

23. The system of claim 20 further comprising a printer for printing address information on exteriors of the envelopes.

24. The system of claim 23 in which the encoded information read by said processor includes intended addressees of the envelopes, and said processor further provides for controlling said printer for printing corresponding address information on the envelopes.

36. A method of accessing information encoded on a substrate in a pattern using an electrically conductive ink comprising the steps of:

relatively moving the encoded substrate past a capacitance sensor in a fashion that permits different portions of the pattern to be measured in different relative positions between the encoded substrate and the capacitance sensor;

successively measuring the different portions of the pattern as the encoded substrate is relatively moved past the capacitance sensor;

detecting variations in capacitance within the pattern of the conductive ink; and

evaluating the detected variations in capacitance for accessing the information encoded within the different portions of the pattern.

37. The method of claim 36 in which said step of relatively moving includes relatively moving the encoded substrate past a capacitance sensor including side-by-side plates.

38. The method of claim 37 including the further step of orienting the side-by-side plates adjacent to a common side of the encoded substrate.

39. The method of claim 36 in which the step of relatively moving includes relatively moving the encoded substrate together with a cover that overlays the pattern of conductive ink on the substrate.

42. The method of claim 36 in which said step of detecting includes monitoring an impedance change in a sensing circuit of the capacitance sensor.

43. The method of claim 36 in which said step of evaluating includes converting the encoded patterns into equivalent alphanumeric characters.

44. The method of claim 36 in which said step of evaluating includes matching the detected variations in capacitance to stored information about similar patterns for reading the encoded information.

45. The method of claim 36 including the further step of printing the electrically conductive ink on the substrate in a pattern that encodes information distinguished by a shape of the pattern.

46. The method of claim 45 in which the pattern is a bar-code pattern.

47. The method of claim 45 in which the conductive ink is invisible.

40. A method of accessing information encoded on a substrate in a pattern using an electrically conductive ink comprising the steps of:

relatively moving the encoded substrate past a capacitance sensor in a fashion that permits different portions of the pattern to be measured in different relative positions between the encoded substrate and the capacitance sensor;

successively measuring the different portions of the pattern as the encoded substrate is relatively moved past the capacitance sensor;

detecting variations in capacitance within the pattern of the conductive ink; and

evaluating the detected variations in capacitance for accessing the information encoded within the different portions of the pattern;

wherein said step of relatively moving includes relatively moving a succession of encoded substrates past the capacitance sensor, at least some of which are printed with a pattern using an electrically conductive ink.

41. The method of claim 40 including the further step of sorting the encoded substrates based on the information accessed from the patterns of electrically conductive ink.

48. A method of processing a succession of substrates including differentially conductive patterns representing encoded information comprising the steps of:

transporting the succession of substrates including the differentially conductive patterns past a capacitance sensor;

measuring variations in capacitance associated with the differentially conductive patterns apparent as contrasts in permittivity between the patterns and the substrates;

deciphering the differentially conductive patterns into recognized units of information; and

distinguishing subsequent processing among the substrates on the basis of the information obtained from their differentially conductive patterns;

wherein the differentially conductive patterns are applied using an electrically conductive ink.

49. The method of claim 48 in which the differentially conductive patterns are applied using a dielectric ink.

50. The method of claim 48 in which the differentially conductive patterns represent information in a form of bar-code.

52. The method of claim 48 in which said step of distinguishing includes sorting the substrates in accordance with the information obtained from their differentially conductive patterns.

51. A method of processing a succession of substrates including differentially conductive patterns representing encoded information comprising the steps of:

transporting the succession of substrates including the differentially conductive patterns past a capacitance sensor;

measuring variations in capacitance associated with the differentially conductive patterns apparent as contrasts in permittivity between the patterns and the substrates;

deciphering the differentially conductive patterns into recognized units of information; and

distinguishing subsequent processing among the substrates on the basis of the information obtained from their differentially conductive patterns;

wherein said step of deciphering includes converting the differentially conductive patterns into equivalent alphanumeric characters.

53. A method of accessing information encoded on a substrate in a pattern using a differentially conductive medium comprising the steps of:

relatively moving a capacitance sensor into proximity with a substrate having an area to which a dielectric medium is applied in a pattern for encoding information;

measuring variations in capacitance associated with the pattern of encoded information apparent as a contrast in permittivity between the dielectric medium and the substrate; and

deciphering the pattern into recognized units of information;

wherein the pattern of encoded information is a bar-code pattern and the pattern of encoded information is decipherable into alphanumeric characters.