US3885229A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Document scanning apparatus
Assignee: NEC Corp
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Filing: 1973-10-25
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Granted: 1975-05-20
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Expires: 1993-10-25
Abstract
Abstract A scanning apparatus for use in a character recognition system is disclosed wherein moving documents are stopped for scanning at a read station. Since a stopped document may not be precisely located for scanning a character on the document, the scanning apparatus defects both the positional and tilt errors of the document to generate corrected positional data for correct scanning of the character on the document. This is accomplished by the scanning apparatus detecting a reference mark and a tilt mark on the document. The detected data is stored as detected positional data, and when a character on the document is scanned, the detected positional data is used to determine an absolute positional data of the scanning start point for which the document stopping positional and tilt errors are corrected.
Inventors
- 👤 Michihiko Negita
- 👤 Yoshiyasu Kikuchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 01:36
CPC Classifications
G; G06; G06V; G06V10/00; G06V10/20; G06V10/24; G06V10/245; G06V30/00; G06V30/10
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
225 words
A document scanning apparatus comprising: means for receiving control data such as positional data including a scanning position coordinate used for scanning information on a document, and storing the control data as present positional data for scanning the document, said means for storing the control data including an X-address register and a Y-address register for storing X and Y coordinate positional data; means for scanning information on the document according to said present positional data; arithmetic means responsive to said means for scanning for periodically adding or subtracting a fixed quantity from the contents of said X-address register until the X-coordinate of said reference mark is detected and for periodically adding or subtracting a fixed quantity from the contents of said Yaddress register until the Y-coordinate of said reference mark is detected; means for storing as a detected positional data the present positional data used when the reference mark is detected, said means for storing the detected positional data including an Xreference register and a Y-reference register for storing X and Y present coordinate positional data, said data being transferred into said X-reference register and said Y-reference register upon the detection of the X-coordinate and the Ycoordinate, respectively, of said reference mark; and means for correcting the document stopping position error depending on the detectIon of said reference mark to carry out the document scanning.
Claim 2
Dependent Claim
225 words
A document scanning apparatus comprising: means for receiving control data such as positional data including a scanning position coordinate used for scanning information on a document, and storing the control data as present positional data for scanning the document, said means for storing the control data including an X-address register and a Y-address register for storing X and Y coordinate positional data; means for scanning information on the document according to said present positional data; arithmetic means responsive to said means for scanning for periodically adding or subtracting a fixed quantity from the contents of said X-address register until the X-coordinate of said reference mark is detected and for periodically adding or subtracting a fixed quantity from the contents of said Yaddress register until the Y-coordinate of said reference mark is detected; means for storing as a detected positional data the present positional data used when the reference mark is detected, said means for storing the detected positional data including an Xreference register and a Y-reference register for storing X and Y present coordinate positional data, said data being transferred into said X-reference register and said Y-reference register upon the detection of the X-coordinate and the Ycoordinate, respectively, of said reference mark; and means for correcting the document stopping position error depending on the detectIon of said reference mark to carry out the document scanning.
Claim 3
Dependent Claim
149 words
A document scanning apparatus as recited in claim 1 further comprising: means for detecting through said scanning operation a tilt mark provided at a location on the document horizontally aligned with said reference mark; a tilt register, said arithmetic means periodically adding or subtracting a fixed quantity from the contents of said Y-address register until the Y-coordinate of said tilt mark is detected, said arithmetic means thereafter subtracting the contents of said Y-reference register from the contents of said Y-address register and storing the result in said tilt register; means for computing a vector difference between the scanning position coordinate and the reference mark coordinate; means for multiplying said vector difference by the tilt of the document to obtain a tilt correction value; and means to vectorially add said tilt correction value to the scanning position coordinate thereby correcting the scanning position according to the tilt of the document.
Claim 4
Dependent Claim
73 words
A document scanning apparatus as recited in claim 2 wherein said means for storing the control data further comprises: an end register for storing the data of the coordinate of the maximum scanning allowable position, said arithmetic means periodically comparing the contents of said X-address register and the contents of said Y-address register, respectively, with the contents of said end register to produce an end of scanning signal when an equality is detected.
Claim 5
Dependent Claim
118 words
A document scanning apparatus as recited in claim 2 further comprising: first, second, third, and fourth digital-to-analog converters, respectively, connected to the outputs of said X-address, X-reference, Y-address, and Y-reference registers and providing analog output signals proportional to the contents of said registers, said means for computing a vector difference including a first analog inverter connected to receive the output of said first analog-to-digital converter, a second analog inverter connected to receive the outputs of said first analog inverter and said second analog-to-digital converter, a third analog inverter connected to receive the output of said third analog-to-digital converter, and a fourth analog inverter connected to receive the outputs of said third analog inverter and said fourth analog-to-digital converter.
Claim 6
Dependent Claim
98 words
A document scanning apparatus as recited in claim 4 wherein said means for multiplying includes a first analog multiplier connected to receive the outputs of said second analog inverter and the contents of said tilt register to convert the signal from said second analog inverter to a signal proportional to the contents of said tilt register, and a second analog multiplier connected to receive the outputs of said fourth analog inverter and the contents of said tilt register to convert the signal from said fourth analog inverter to a signal proportional to the contents of said tilt register.
Claim 7
Dependent Claim
75 words
A document scanning apparatus as recited in claim 5 wherein said means to vectorially add includes a fifth analog inverter connected to receive the outputs of said first analog-to-digital converter and said second analog multiplier to produce an X-address signal for said means for scanning, and a sixth analog inverter connected to receive the outputs of said third analog-to-digital converter and said first analog multiplier to produce a Y-address signal for said means for scanning.
Claim 8
Dependent Claim
98 words
A document scanning apparatus as recited in claim 6 wherein said means for scanning includes a cathode-ray tube and drive circuit means responsive to said X-address signal and said Y-address signal for scanning said document with a scanning beam, and wherein said means detecting includes a photodetector means positioned to sense the reflection of said scanning beam from said document, said photodetector means supplying a signal discriminated as either black or white to said arithmetic means for coNtrolling said periodic adding or subtracting of a fixed quantity from the contents of said X-address register or said Y-address register.
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) | 1978-05-19 | 1978-11-18 | 1979-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-19 | 1982-11-18 | 1983-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-19 | 1986-11-18 | 1987-05-20 | $7700.00 | Window Closed / Lapsed |