US4151410A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Document processing, jam detecting apparatus and process
Assignee: Unisys Corp
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Filing: 1977-12-02
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Granted: 1979-04-24
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Expires: 1997-12-02
Abstract
Abstract An apparatus and process for detecting document jams in a document processing apparatus by detecting the translucency of the documents. The disclosed apparatus includes a transport path for guiding documents and drive wheels for moving the documents along the transport path. An LED light source located on one side of the transport path illuminates at least a portion of the moving document as it passes along the transport path. A phototransistor light detector located on the other side of the transport path detects light from the LED that passes through translucent portions of the document. Electronics connected to the light detector indicate a document jam when the translucency of a document is generally unchanged for a period of time while the document is between the light source and light detector. The electronics includes circuitry for detecting the presence of a document, circuitry for detecting the absence of rapid changes in document translucency and circuitry for remembering the absence of such rapid changes in document translucency.
Inventors
- 👤 Andrew H. McMillan
- 👤 William B. Templeton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:23
CPC Classifications
B; B65; B65H; B65H7/00; B65H7/02; B65H7/14; G; G01; G01V; G01V8/00; G01V8/10; G01V8/12
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
119 words
An apparatus for detecting a document jam in a system that moves documents, said documents having first and second broad, opposite surfaces; said apparatus comprising: means located adjacent the first surface of said moving document for illuminating at least a portion of said moving document; means located adjacent the opposite surface of said moving document for detecting the magnitude of light that passes through translucent portions of the document as it is between said illuminating means and said detecting means; and electronic means connected to said detecting means for indicating a document jam when the translucency of said document is generally unchanged for a period of time while the document is between the illuminating means and the detecting means.
Claim 2
Independent Claim
119 words
An apparatus for detecting a document jam in a system that moves documents, said documents having first and second broad, opposite surfaces; said apparatus comprising: means located adjacent the first surface of said moving document for illuminating at least a portion of said moving document; means located adjacent the opposite surface of said moving document for detecting the magnitude of light that passes through translucent portions of the document as it is between said illuminating means and said detecting means; and electronic means connected to said detecting means for indicating a document jam when the translucency of said document is generally unchanged for a period of time while the document is between the illuminating means and the detecting means.
Claim 3
Dependent Claim
41 words
The jam detecting apparatus according to claim 1 wherein said indicating means indicates a document jam when the translucency of said document is generally unchanged for a predetermined time while the document is between the illuminating means and the detecting means.
Claim 4
Dependent Claim
25 words
The jam detecting apparatus according to claim 1 wherein said indicating means comprises means for detecting rapid changes in the output of said detecting means.
Claim 5
Dependent Claim
40 words
The jam detecting apparatus according to claim 3 wherein said indicating means further comprises; means for remembering rapid changes in the output of said detecting means; and means for deciding when the output of said detecting means is generally unchanged.
Claim 6
Dependent Claim
30 words
The jam detecting apparatus according to claim 4 wherein said indicating means further comprises means for designating when a document is present between said illuminating means and said detecting means.
Claim 7
Dependent Claim
17 words
The jam detecting apparatus according to claim 4 wherein said illuminating means comprises an infrared light source.
Claim 8
Dependent Claim
25 words
The jam detecting apparatus according to claim 4 wherein said detecting means provides a non-linear relationship between the light it senses and its electrical output.
Claim 9
Dependent Claim
127 words
A document processing apparatus that processes moving documents and indicates a document jam therein, comprising: a transport path for guiding documents; means for moving documents along said transport path, means located on one side of said transport path for illuminating at least a portion of the moving document as it passes along said transport path; means located on the other side of said transport path for detecting light from said illuminating means that passes through translucent portions of the document as the document passes along said transport path; and electronic means connected to said detecting means for indicating a document jam when the translucency of the document is generally unchanged for a period of time while the document is between the illuminating means and the detecting means.
Claim 10
Dependent Claim
127 words
A document processing apparatus that processes moving documents and indicates a document jam therein, comprising: a transport path for guiding documents; means for moving documents along said transport path, means located on one side of said transport path for illuminating at least a portion of the moving document as it passes along said transport path; means located on the other side of said transport path for detecting light from said illuminating means that passes through translucent portions of the document as the document passes along said transport path; and electronic means connected to said detecting means for indicating a document jam when the translucency of the document is generally unchanged for a period of time while the document is between the illuminating means and the detecting means.
Claim 11
Dependent Claim
41 words
The document processing apparatus according to claim 8 wherein said indicating means indicates a document jam when the translucency of the document is generally unchanged for a predetermined time while the document is between the illuminating means and the detecting means.
Claim 12
Dependent Claim
25 words
The document processing apparatus according to claim 8 wherein said indicating means comprises means for detecting rapid changes in the output of said detecting means.
Claim 13
Dependent Claim
19 words
The document processing apparatus according to claim 10 wherein said rapid change detecting means comprises a high pass filter.
Claim 14
Dependent Claim
40 words
The document processing apparatus according to claim 10 wherein said indicating means further comprises: means for remembering rapid changes in the output of said detecting means; and means for deciding when the output of said detecting means is generally unchanged.
Claim 15
Dependent Claim
25 words
The document processing apparatus according to claim 12 wherein: said remembering means comprises a low pass filter; and said deciding means comprises a trigger circuit.
Claim 16
Dependent Claim
30 words
The document processing apparatus according to claim 12 wherein said indicating means further comprises means for designating when a document is present between said illuminating means and said detecting means.
Claim 17
Dependent Claim
37 words
The document processing apparatus according to claim 14 wherein said document present designating means monitors the current through said light detecting means and indicates a document is present when the current is less than a predetermined value.
Claim 18
Dependent Claim
100 words
The document processing apparatus according to claim 8 wherein said indicating means comprises: means for amplifying the output of said detecting means; means responsive to the output of said amplifying means for detecting rapid changes in the output of said amplifying means; comparator means responsive to the output of said rapid change detecting means for indicating when said rapid changes exceed a predetermined value; means responsive to the output of said comparator means for remembering the output of said comparator means; and deciding means responsive to the output of said remembering means for deciding when a document jam has occurred.
Claim 19
Dependent Claim
49 words
The document processing apparatus according to claim 16 wherein: said amplifying means comprises an amplifier circuit; said rapid change detecting means comprises a high pass filter; said comparator means comprises a comparator circuit; said remembering means comprises a low pass filter; and said deciding means comprises a trigger circuit.
Claim 20
Dependent Claim
17 words
The document processing apparatus according to claim 8 wherein said illuminating means comprises an infrared light source.
Claim 21
Dependent Claim
18 words
The document processing apparatus according to claim 18 wherein said infrared light source comprises a light emitting diode.
Claim 22
Dependent Claim
22 words
The document processing apparatus according to claim 8 wherein said detecting means provides a nonlinear light input to electrical output transfer characteristic.
Claim 23
Dependent Claim
22 words
The document processing apparatus according to claim 20 wherein said detecting means provides a logarithmic light input to electrical output transfer characteristic.
Claim 24
Dependent Claim
15 words
The document processing apparatus according to claim 20 wherein said detecting means comprises a phototransistor.
Claim 25
Dependent Claim
87 words
A process for moving documents and detecting when the documents jam, comprising: providing a transport path for guiding the documents; moving documents along the transport path; illuminating a portion of the document from one side the transport path; detecting light that passes through translucent portions of the document; and indicating a document jam when the translucency of the document is generally unchanged for a period of time while the document is being illuminated and the light that passes through translucent portions of the document is being detected.
Claim 26
Dependent Claim
87 words
A process for moving documents and detecting when the documents jam, comprising: providing a transport path for guiding the documents; moving documents along the transport path; illuminating a portion of the document from one side the transport path; detecting light that passes through translucent portions of the document; and indicating a document jam when the translucency of the document is generally unchanged for a period of time while the document is being illuminated and the light that passes through translucent portions of the document is being detected.
Claim 27
Dependent Claim
29 words
The process according to claim 23 wherein the step of indicating a document jam comprises detecting rapid changes in the light that passes through translucent portions of the document.
Claim 28
Dependent Claim
46 words
The process according to claim 24 wherein the step of indicating a document jam further comprises: remembering rapid changes in the light that passes through translucent portions of the document; and deciding when the light that passes through translucent portions of the document is generally unchanged.
References Cited (Backward Citations)
US3815895A
Cited
US3944933A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-04-23 | 1982-10-23 | 1983-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-23 | 1986-10-23 | 1987-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-23 | 1990-10-23 | 1991-04-24 | $7700.00 | Window Closed / Lapsed |