US4748480A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Controlled authentic document recognition equipment
Assignee: Xerox Corp
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Filing: 1987-06-12
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Granted: 1988-05-31
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Expires: 2007-06-12
Abstract
Abstract This invention relates to sensitive or classified documents utilizing specially prepared paper containing a unique substance which will, in the presence of sensors incorporated within a document copier which constantly monitor the field of view for the presence of this unique substance, interrupt the operation of this document copier. Within the copier housing, adjacent the illumination and optical apparatus, a lens gathers some of the reflected light from a document to be copied. This light is then passed through three (3) narrow band spectral filters to three (3) associated detectors. Subsequent circuitry responds to the detected light at the predetermined wavelengths, if present, and, when appropriate, interrupts the operation of the copier and/or sounds an alarm or triggers a camera.
Inventors
- 👤 Paul F. Jacobs
- 👤 Thomas A. Whatley
- 👤 John D. Worden
- 👤 William D. Green
- 👤 Kenneth I. Gustafson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:23
CPC Classifications
G; G03; G03G; G03G21/00; G03G21/04; G03G21/046
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
117 words
Apparatus for preventing the unauthorized reproduction of classified, or proprietary, or other documents on a photocopier comprising: means adjacent the illumination and/or optical apparatus of said photocopier for detecting light reflected from said document, said detecting means being independent of the normal document reproduction apparatus, said detecting means including lens means for gathering and focussing some of the reflected light from a document on said photocopier to be copied, a plurality of spectral filter means receiving said focussed light and responsive to predetermined frequency bands to respond to a predetermined chemical compound group. means responsive to the light transmitted by said spectral filter means for generating electrical signals to at least interrupt the operation of said photocopier.
Claim 2
Dependent Claim
117 words
Apparatus for preventing the unauthorized reproduction of classified, or proprietary, or other documents on a photocopier comprising: means adjacent the illumination and/or optical apparatus of said photocopier for detecting light reflected from said document, said detecting means being independent of the normal document reproduction apparatus, said detecting means including lens means for gathering and focussing some of the reflected light from a document on said photocopier to be copied, a plurality of spectral filter means receiving said focussed light and responsive to predetermined frequency bands to respond to a predetermined chemical compound group. means responsive to the light transmitted by said spectral filter means for generating electrical signals to at least interrupt the operation of said photocopier.
Claim 3
Dependent Claim
44 words
The apparatus as set forth in claim 1 wherein said plurality of spectral filter means includes at least three spectral filters responsive to three separate wavelengths of light reflected from said document, said three separate wavelengths being identifiable with said predetermined chemical compound group.
Claim 4
Dependent Claim
40 words
The apparatus as set forth in claim 2 wherein said chemical compound group is coated on or made in the paper stock of said document to be copied such that such documents render the copier inoperative and/or initiate other actions.
Claim 5
Dependent Claim
38 words
The apparatus as set forth in claim 2 wherein said chemical compound group being from a family of compositions having four isoindole groups linked by four nitrogen atoms in such a manner as to form a conjugated chain.
Claim 6
Independent Claim
116 words
A method of preventing or monitoring the unauthorized reproduction of classified, or proprietary, or other documents on a photocopier comprising generating a source of light to illuminate a document to be copied detecting light reflected from said document, said light detection being independent of the normal document reproduction apparatus, said step of detecting including gathering and focussing some of the detected light reflected from said document to be copied, filtering said focussed light and responsive to predetermined frequency bands of light which correspond to a predetermined chemical compound group, and generating electrical signals to at least interrupt the operation of said photocopier upon detection of said light reflected in correspondence to a predetermined chemical compound group.
Claim 7
Independent Claim
116 words
A method of preventing or monitoring the unauthorized reproduction of classified, or proprietary, or other documents on a photocopier comprising generating a source of light to illuminate a document to be copied detecting light reflected from said document, said light detection being independent of the normal document reproduction apparatus, said step of detecting including gathering and focussing some of the detected light reflected from said document to be copied, filtering said focussed light and responsive to predetermined frequency bands of light which correspond to a predetermined chemical compound group, and generating electrical signals to at least interrupt the operation of said photocopier upon detection of said light reflected in correspondence to a predetermined chemical compound group.
Claim 8
Dependent Claim
55 words
The method as set forth in claim 5 further including coating or manufacturing the paper stock of said document to be copied with said chemical compound group, wherein said compound group comprises a family of compositions having four isoindole groups linked by four nitrogen atoms in such a manner as to form a conjugated chain.
Claim 9
Dependent Claim
45 words
The method as set forth in claim 6 wherein said step of filtering includes providing at least three filters responsive to three separate wavelengths of light reflected from said document to be copied, said three separate wavelengths being identifiable with said predetermined chemical compound group.
Claim 10
Dependent Claim
120 words
Apparatus for preventing the unauthorized reproduction of classified, or proprietary, or other documents on a photocopier comprising: means adjacent the illumination and/or optical apparatus of said photocopier for detecting light reflected from said document, said detecting means being independent of the normal document reproduction apparatus, said detecting means including lens means for gathering and focussing some of the reflected light from a document on said photocopier to be copied, a plurality of spectral filter means receiving said focussed light and responsive to predetermined frequency bands to respond to a predetermined chemical compound group, and means responsive to the light transmitted by said spectral filter means for generating electrical signals to interrupt the operation of said photocopier and/or initiate other actions.
Claim 11
Dependent Claim
120 words
Apparatus for preventing the unauthorized reproduction of classified, or proprietary, or other documents on a photocopier comprising: means adjacent the illumination and/or optical apparatus of said photocopier for detecting light reflected from said document, said detecting means being independent of the normal document reproduction apparatus, said detecting means including lens means for gathering and focussing some of the reflected light from a document on said photocopier to be copied, a plurality of spectral filter means receiving said focussed light and responsive to predetermined frequency bands to respond to a predetermined chemical compound group, and means responsive to the light transmitted by said spectral filter means for generating electrical signals to interrupt the operation of said photocopier and/or initiate other actions.
Claim 12
Independent Claim
118 words
A method of preventing or monitoring the unauthorized reproduction of classified, or proprietary, or other documents on a photocopier comprising generating a source of light to illuminate a document to be copied, detecting light reflected from said document, said light detection being independent of the normal document reproduction apparatus, said step of detecting including gathering and focussing some of the detected light reflected from said document to be copied, filtering said focussed light and responsive to predetermined frequency bands of light which correspond to a predetermined chemical compound group, and generating electrical signals to interrupt the operation of said photocopier and/or initiate other actions upon detection of said light reflected in correspondence to a predetermined chemical compound group.
Claim 13
Independent Claim
118 words
A method of preventing or monitoring the unauthorized reproduction of classified, or proprietary, or other documents on a photocopier comprising generating a source of light to illuminate a document to be copied, detecting light reflected from said document, said light detection being independent of the normal document reproduction apparatus, said step of detecting including gathering and focussing some of the detected light reflected from said document to be copied, filtering said focussed light and responsive to predetermined frequency bands of light which correspond to a predetermined chemical compound group, and generating electrical signals to interrupt the operation of said photocopier and/or initiate other actions upon detection of said light reflected in correspondence to a predetermined chemical compound group.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-05-31 | 1991-11-30 | 1992-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-31 | 1995-11-30 | 1996-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-31 | 1999-11-30 | 2000-05-31 | $7700.00 | Window Closed / Lapsed |