US3761876A
Expired / Lapsed
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Recognition unit for optical character reading system
Assignee: Recognition Equipment Inc
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Filing: 1971-07-28
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Granted: 1973-09-25
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Expires: 1991-07-28
Abstract
Abstract A recognition unit accepts normalized character data from a multicell, single columnar retina across which a character image is scanned and converts the serial stream of digital character data into a parallel format for each scan and then correlates the data by comparing each cell with a composite of the surrounding cells to establish a black or white digital signal for each cell position. The signals are stored in a matrix array which is vertically analyzed to locate the character dependent cells. The character data is then shifted into a storage matrix and applied to a plurality of digital character masks for selection of the character represented by the data.
Inventors
- 👤 L Flaherty
- 👤 W Hale
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:20
CPC Classifications
G; G06; G06V; G06V10/00; G06V10/20; G06V10/28; G06V10/30; G06V10/36; G06V10/70; G06V10/74; G06V10/75
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
197 words
A method of correlating the comparative blackness of a data point cell within an array of cells which successively views each of a train of characters to generate a black/white decision signal for said cell compriSing the steps of: summing signals from a set of cells surrounding the data point cell with the signal from the data point cell; biasing said sum in the black sense by a programmable quantity; multiplying the signal from the data point cell by the number of cells in said set; comparing the biased sum with the multiplied data point cell signal to generate a relative black signal if the cell value sum is the greater; generating a programmable absolute black threshold signal; comparing the data point cell signal with said absolute black threshold signal to generate an absolute black signal if the cell value signal is the greater; generating a black output signal for the data point cell in response to the presence of either a relative black signal or an absolute black signal; and generating a white output signal for the data point cell in response to the absence of both a relative black signal and an absolute black signal.
Claim 2
Independent Claim
197 words
A method of correlating the comparative blackness of a data point cell within an array of cells which successively views each of a train of characters to generate a black/white decision signal for said cell compriSing the steps of: summing signals from a set of cells surrounding the data point cell with the signal from the data point cell; biasing said sum in the black sense by a programmable quantity; multiplying the signal from the data point cell by the number of cells in said set; comparing the biased sum with the multiplied data point cell signal to generate a relative black signal if the cell value sum is the greater; generating a programmable absolute black threshold signal; comparing the data point cell signal with said absolute black threshold signal to generate an absolute black signal if the cell value signal is the greater; generating a black output signal for the data point cell in response to the presence of either a relative black signal or an absolute black signal; and generating a white output signal for the data point cell in response to the absence of both a relative black signal and an absolute black signal.
Claim 3
Dependent Claim
125 words
A method set forth in claim 1 wherein the step of summing signals from surrounding cells includes the steps of: shifting signals from adjacent cells through the respective ones of a plurality of multistage shift registers, the number of said registers being equal to one dimension of the surrounding cell array and the number of stages in each register being equal to the other orthogonal dimensions; summing each signal as it is shifted out of the last stage of the respective registers; subtracting the cell signals in each first stage from the register sum to form a running sum of all cell signals in the register; and summing and running sums of all the registers to form a composite matrix sum of surrounding cell signals.
Claim 4
Independent Claim
206 words
A system for correlating the comparative blackness of a data point cell within an array of cells which successively view each of a train of characters to reach a black/white decision signal for said cell comprising: means for summing signals from a set of cells surrounding the data point cell with the signal from the data point cell; means for biasing said sum in the black direction by a programmable quantity; means for multiplying the signal from the data point cell by the number of cells in said set; means for comparing the biased sum with the multiplied data cell signal to generate a relative black signal if the cell value sum is the greater; means for generating a programmable absolute black signal; means for comparing the data point cell signal with said absolute black threshold signal to generate an absolute black signal if the cell value signal is the greater; means for generating a black signal for the data point cell in response to the presence of either a relative black signal or an absolute black signal; and means for generating a white signal for the data point cell in response to the absence of both a relative black signal and an absolute black signal.
Claim 5
Independent Claim
206 words
A system for correlating the comparative blackness of a data point cell within an array of cells which successively view each of a train of characters to reach a black/white decision signal for said cell comprising: means for summing signals from a set of cells surrounding the data point cell with the signal from the data point cell; means for biasing said sum in the black direction by a programmable quantity; means for multiplying the signal from the data point cell by the number of cells in said set; means for comparing the biased sum with the multiplied data cell signal to generate a relative black signal if the cell value sum is the greater; means for generating a programmable absolute black signal; means for comparing the data point cell signal with said absolute black threshold signal to generate an absolute black signal if the cell value signal is the greater; means for generating a black signal for the data point cell in response to the presence of either a relative black signal or an absolute black signal; and means for generating a white signal for the data point cell in response to the absence of both a relative black signal and an absolute black signal.
Claim 6
Dependent Claim
130 words
A system as set forth in claim 3 wherein said means for summing signals from surrounding cells includes; means for shifting signals from adjacent cells through respective ones of a plurality of multistage shift registers, the number of said registers being equal to one dimension of the surrounding cell array and the number of stages in each register being equal to the other orthogonal dimension; means for summing each signal as it is shifted out of the last stage of the respective register; means for subtracting the cell signals in each first stage from the register sum to form a running sum of all cell signals in the register, and means for summing the running sums of all the registers to form a composite matrix sum of surrounding cell signals.
Claim 7
Independent Claim
299 words
A system for recognizing characters from data samples of a vertical array of photocells comprising: means for summing signals from a set of cells surrounding a data point cell with the signal from the said point cell, means for biasing said sum in the black sense by a programmable quanTity, means for multiplying the signal from the data point cell by the number of cells in said set, means for comparing the biased sum with the multiplied data point cell signal to generate a relative black signal if the cell value sum is the greater, means for generating a programmable absolute black threshold signal, means for comparing the data point cell signal with said absolute black threshold signal to generate an absolute black signal if the cell value signal is the greater, means for generating a black output signal for the data point cell in response to the presence of either a relative black signal or an absolute black signal, means for generating a white output signal for the data point cell in response to the absence of both a relative black signal and an absolute black signal, means for simultaneously applying the white output signals to a plurality of black masks and for inverting the said white output signals and applying the signals to a plurality of white masks, means for monitoring the output voltage from the plurality of masks, means for comparing the output signals from selected masks with a first preselected threshold voltage signal and storing the output signal if it exceeds the threshold, means for amplifying said stored voltage signal, and means for comparing the amplified voltage with a second preselected voltage signal greater than said first preselected signal and producing a character recognition signal representing the character associated with the particular mask being monitored.
Claim 8
Independent Claim
299 words
A system for recognizing characters from data samples of a vertical array of photocells comprising: means for summing signals from a set of cells surrounding a data point cell with the signal from the said point cell, means for biasing said sum in the black sense by a programmable quanTity, means for multiplying the signal from the data point cell by the number of cells in said set, means for comparing the biased sum with the multiplied data point cell signal to generate a relative black signal if the cell value sum is the greater, means for generating a programmable absolute black threshold signal, means for comparing the data point cell signal with said absolute black threshold signal to generate an absolute black signal if the cell value signal is the greater, means for generating a black output signal for the data point cell in response to the presence of either a relative black signal or an absolute black signal, means for generating a white output signal for the data point cell in response to the absence of both a relative black signal and an absolute black signal, means for simultaneously applying the white output signals to a plurality of black masks and for inverting the said white output signals and applying the signals to a plurality of white masks, means for monitoring the output voltage from the plurality of masks, means for comparing the output signals from selected masks with a first preselected threshold voltage signal and storing the output signal if it exceeds the threshold, means for amplifying said stored voltage signal, and means for comparing the amplified voltage with a second preselected voltage signal greater than said first preselected signal and producing a character recognition signal representing the character associated with the particular mask being monitored.
Claim 9
Independent Claim
194 words
A system for recognizing characters from data samples of a vertical array of photocells, comprising in combination: means for correlating the data samples into a plane of white data samples associated with white areas of the vertical samples through the character, a plurality of black masks each representing a character to be recognized by the system and generating an output signal therefor, a plurality of white masks equal in number to said plurality of black masks and also individually associated with a character to be recognized by the system and generating an output signal therefor, means for inverting the white data samples into black data samples, means for simultaneously applying the white data samples to the plurality of black masks and the black data samples to the plurality of white masks, means for monitoring the output signals from the plurality of black and white masks, means for comparing the output signals from selected masks with a preselected threshold voltage signal, means for storing the output signal if it exceeds the threshold, and means for producing a character recognition signal from the stored output signal representing a character associated with a particular mask being monitored.
Claim 10
Independent Claim
194 words
A system for recognizing characters from data samples of a vertical array of photocells, comprising in combination: means for correlating the data samples into a plane of white data samples associated with white areas of the vertical samples through the character, a plurality of black masks each representing a character to be recognized by the system and generating an output signal therefor, a plurality of white masks equal in number to said plurality of black masks and also individually associated with a character to be recognized by the system and generating an output signal therefor, means for inverting the white data samples into black data samples, means for simultaneously applying the white data samples to the plurality of black masks and the black data samples to the plurality of white masks, means for monitoring the output signals from the plurality of black and white masks, means for comparing the output signals from selected masks with a preselected threshold voltage signal, means for storing the output signal if it exceeds the threshold, and means for producing a character recognition signal from the stored output signal representing a character associated with a particular mask being monitored.
Claim 11
Dependent Claim
45 words
A system for recognizing a character as set forth in claim 6 wherein said means for monitoring includes means for summing the output voltage for a white mask for a particular character with the output voltage for the corresponding black mask for the same character.
Claim 12
Dependent Claim
43 words
A system for recognizing a character as set forth in claim 6 wherein said means for producing a character recognition signal includes means for comparing the output signals with a second preselected threshold voltage signal greater than said first preselected threshold voltage signal.
Claim 13
Dependent Claim
36 words
A system as set forth in claim 6 wherein the said monitoring means includes a peak amplifier associated with each mask set and wherein only selected groups of peak amplifiers are enabled for particular character groups.
Claim 14
Dependent Claim
24 words
A system as set forth in claim 6 which also includes means responsive to said stored output signal for producing a character present signal.
Claim 15
Dependent Claim
44 words
A system as set forth in claim 6 wherein said second preselected threshold voltage is produced by means for generating a descending staircase voltage and which also includes means for counting the number of steps of voltage descent before the compared voltages are equal.
Claim 16
Independent Claim
253 words
A system for recognizing digitized data bit words produced by repeatedly scanning and sampling the outputs of a plurality of photocells during passage of an image of a character across the photocells, comprising: means for converting a serial sample stream of data bit words, each of which represent a photocell output, into a set of parallel data words for each scan, means for storing the parallel data words from a plurality of successive scans in a first matrix array, means for correlating said parallel data words to produce either a black or white signal from each data bit word of the stored samples, primary means for storing the correlated signals in a matrix array, said primary means having positions slightly greater in number than the number of parallel data words stored in the first matrix array, secondary means for storing the correlated signals, said secondary means having cells in number equal to the size of the character being scanned, means for shifting a plurality of overlapping segments of the black or white signals stored in the primary means into the secondary means to jitter the signals and eliminate error due to slight vertical misalignment of the character signals within the primary means, means for applying the stored correlated signals from the secondary means to a plurality of character mask sets, and means for monitoring the outputs from the plurality of mask sets to select the mask having the largest output response as being the one associated with the character comprising the stored signals.
Claim 17
Independent Claim
253 words
A system for recognizing digitized data bit words produced by repeatedly scanning and sampling the outputs of a plurality of photocells during passage of an image of a character across the photocells, comprising: means for converting a serial sample stream of data bit words, each of which represent a photocell output, into a set of parallel data words for each scan, means for storing the parallel data words from a plurality of successive scans in a first matrix array, means for correlating said parallel data words to produce either a black or white signal from each data bit word of the stored samples, primary means for storing the correlated signals in a matrix array, said primary means having positions slightly greater in number than the number of parallel data words stored in the first matrix array, secondary means for storing the correlated signals, said secondary means having cells in number equal to the size of the character being scanned, means for shifting a plurality of overlapping segments of the black or white signals stored in the primary means into the secondary means to jitter the signals and eliminate error due to slight vertical misalignment of the character signals within the primary means, means for applying the stored correlated signals from the secondary means to a plurality of character mask sets, and means for monitoring the outputs from the plurality of mask sets to select the mask having the largest output response as being the one associated with the character comprising the stored signals.
Claim 18
Dependent Claim
118 words
A system as set forth in claim 12 wherein each retina scan includes signals from a number of sampled cells greater than the number of cells exposed to the character image and wherein said means for storing correlated data includes: means for storing the correlated cell signals within an analysis matrix array having storage positions at least as large as the number of samples taken in the scan; means for analyzing the signals stored within the matrix to determine the location of the character cells within the matrix; and means for shifting the matrix positions containing the character into a primary storage array having a number of positions approximately equal to the number of cells in the character.
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) | 1976-09-24 | 1977-03-26 | 1977-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-24 | 1981-03-26 | 1981-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-24 | 1985-03-26 | 1985-09-25 | $7700.00 | Window Closed / Lapsed |