Title of Invention

A DEVICE FOR DETERMINING THE INSTANTNEOUS TRAVEL SPEED OF DOCUMENTS

Abstract A device for determining the instantaneous travel speed of documents having control characters which are electronically exploitable by a sensor. The instantaneous speed is determined as a function of the detection of the control characters by exploiting characteristics which are specific to the control characters. For example, the method is applied to control characters including bars with standardized spaces. The instantaneous speed is determined as a function of the passage duration of two bars in front of the sensor and of the nominal space separating the two bars.
Full Text



"* The present invention relates to a device for determining the instantaneous travel speed of documents, more particularly for reading standardized control characters on checks and for printing text thereon.
Discussion of the Related Art.
Presently, most checks have control characters at their bottom, indicating the account number, the bank code, and so on. These control characters are both readable by the user and exploitable by a character recognition device.
Fig. 1 represents some characters (digits 1 to 7) from the CMC7 set defined by the ISO 1004 standard. This set of characters is used, for example, in France and in some European countries. Each character is formed by seven vertical bars of constant width. Among the six spaces separating the bars of a character, two spaces are wide and four are narrow. The narrow spaces have a 0.3-mm standardized length and the wide spaces a 0.5-mm standardized length. Combining the various successive wide and narrow spaces provides digits from 0 to 9 and some other control characters which can be found on checks.
The CMC? characters are printed with a magnetizable ink. Thus, a processing system detects the successive bars through a vertical linear magnetic sensor while the check travels. Generally, a magnetic head magnetizes the bars before they pass in front of the sensor.
Fig. 2 represent some characters (the same digits as those in Fig. 1) from the E13B set which is predominantly used in Anglo-Saxon countries. The E13B set is defined by the ANSI X 3.2 Rev. 1976 standard. Each character is printed with a magnetizable ink according to a specific pattern (with portions having a varying width). A vertical linear magnetic sensor, in front of which the characters pass, provides, as represented for digits 2 and 5 in Fig. 2, pulses of amplitude, polarity, and distance which vary depending upon the areas of the character scanned by the sensor.
DUPLICATE

For example, as represented for digits 2 and 5, the signal pro¬vided by the sensor has, at the beginning of the character, a long positive pulse followed by a short negative pulse and, at the end of the character, a short positive pulse followed by a long negative pulse.
It is only the distance between the pulses at the be¬ginning of the character and the pulses at the end of the charac¬ter which differentiates digit 2 from digit 5.
A device for processing E13B characters stores the waveform of the sensor's output signal, in the form of samples, and carries out a shape recognition on this waveform by comparing it with predetermined shapes corresponding to the characters.
To recognize any of the two above-described sets of characters, it is necessary to constantly know the travel speed of a check so as, for the CMC7 set, to precisely differentiate the wide spaces from the narrow spaces and, for the E13B set, to differentiate similar shapes which only differ by a time scale variation, like the shapes associated with digits 2 and 5.
The detection of the travel speed of checks is not only necessary for the recognition of the control characters. Indeed, it is increasingly customary, in order to accelerate the flow of customers at the cash desks in department stores, to print the amount, order, place and date on the checks. The travel speed of the checks should be accurately known for the printing to be regular and readable.
The most frequently used solution to accurately know the travel speed of checks is to draw the checks by a constant speed motor. Using a motor makes the processing device expensive and cumbersome. SUMMARY OF THE INVENTION
An object of the present invention is to provide a method for detecting the instantaneous travel speed of documents, such as checks, which are manually driven in front of a control character sensor.

For this purpose, it could be devised to provide the processing system with a speed sensor; however the use of a speed sensor is as expensive as the use of a motor.
Thus, a more particular object of the present invention is to detennine the travel speed without using a speed sensor.
To achieve these objects, the present invention pro¬vides a method for determining the instantaneous travel speed of documents having control characters which are electronically ex¬ploitable by a sensor, in which the instantaneous speed is deter¬mined as a function of the detection of the control characters by exploiting characteristics which are specific to the control characters.
According to an embodiment of the invention, the method is applied to control characters including bars with standardized spaces. The instantaneous speed is determined as a function of the run duration of two bars in front of the sensor and of the nominal space separating the two bars.
According to an embodiment of the invention, the method is applied to control cheiracters having standardized patterns for shape recognition of "the signal provided by the sensor. The method includes the steps of detecting the control characters with two sensors placed at a predetermined distance one from the other; sampling the respective signals provided by the sensors; for a sample of the second sensor along the travel direction of the document, finding among the samples of the first sensor the one which best corresponds to the sample; and determining the in¬stantaneous speed as a function of the distance separating the sensors and of the time distance separating the sample from the best corresponding sample.
The invention can be used for printing a text on a document having control characters. Printing is then synchronized with the traveling of the document from the instantaneous speed determined in the way mentioned above.
According to an embodiment of the invention, the speed is extrapolated, between two speed determinations, from the last determined speed and a corresponding acceleration.

The invention can be used in a method for recognizing control character on traveling documents, In this case, the method includes the steps of determining the instantaneous travel speed in the way mentioned above; storing the samples of one of the two sensors with the corresponding speeds; normalizing the waveform of the signal output by one of the sensors with the samples and the corresponding speeds; and applying a shape recognition to the normalized waveform.
Accordingly, the present invention provides a device for determining the instantaneous travel speed of documents having electronically exploitable control characters provided with bars of standardized inter-spaces, comprising;
1. two sensors (A & B) placed at a predetermined distance (d) from one another for detecting the control characters, instantaneous speed being determined as a function of tlie passage duration of two bars in front of the sensor and the speed separating said bars,
2. sampling means for sampling the respective signals from said sensors,
3. storing means for storing the samples of one of said sensors with the corresponding speeds,
4. sample means for sampling the signals from the second sensor B along the fravel direction of said document,
5. fmding means for finding a san^le that corresponds best to the samples of the first sensor,
6. normalizing means for normalizing the waveform of the signal output from one of said sensors with said samples and the corresponding speeds,
7. shape recognition means for applying shape recognition to said normalized waveform and
8. speed determining means for determining the instantaneous speed as a function of the distance separating the sensors and of the time distance separating said sample fi^m the best corresponding sample.

The foregoing and other objects, features, aspects and advantages of the invention will become apparent from the following detailed description of the present invention when taken in conjunction with reference to the accompanying drawings, in which;
Figs. 1 and 2, above described, are exemplary sets of control characters used in the processing of checks;
Fig. 3 is an exemplary flowchart illustrating the method for determining the travel speed according to the present invention, applied to the set of characters of Fig. 1;
Fig. 4 represents a sensor according to the present invention for determining the travel speed from the set of characters of Fig. 2;
Fig. 5 represents an example of signals provided by the sensor of Fig, 4; and
Fig. 6 represents an exemplary flow chart illustrating the method according to the present invention applied to the set of characters of Fig. 2.
To determine the travel speed of documents with CMC7 control characters (Fig.l), the invention mainly dates each detection of the passage of a bar in front of a sensor serving to read these control characters, and measures the time elapsed from the detection of the previous bar. Since the spaces between the bars of a character are standardize4 it is sufficient to divide the standardized distance by this elapsed time to obtain the travel speed.
The difficulty lies in that bars are not regularly spaced, since each character
includes two wide spaces and four

narrow spaces. Thus, it is necessary to know whether it is the wide or the narrow space that must be divided by the elapsed time.
To overcome this difficulty, the present invention uses a time threshold beyond which a space is supposed to be wide, this time threshold being adjusted as a function of the last found instantaneous speed. Since the wide and narrow spaces are 0.5 mm and 0.3 mm, respectively, the threshold is adjusted, for example, to correspond to a 0.4-mm wide space as a function of the last found speed.
When printing a text on a check according to the inven¬tion, the speed information is used to determine at which time a new vertical row of points must be printed for forming a printed character. The speed foiond for the last bar is integrated to de¬termine the traveled distance and therefore the times at which vertical rows of points must be printed. Between two bars, more particularly the bars separated by a wide space or by an inter-character space, the speed may vary significantly, to such an ex¬tent that the regularity of printing is impaired before the next " bar comes. In addition, this significant variation can cause an erroneous adjustment of the time threshold to differentiate the wide spaces from the narrow spaces.
To avoid this drawback, preferably, the acceleration is calculated at each bar as a function of the last two determined speeds and of the time measured between the two corxesponding bars, which enables to extrapolate the speed until the arrival of the next bar. This enables an extrapolation of the time threshold at the same time.
Of course, the acceleration may also vaary theoreti¬cally. In practice, it has proven that the acceleration, during manual processing, is substantially constant. Therefore, the ac¬celeration does not need to be extrapolated.
Fig. 3 represents an exemplary flowchart illustrating in more detail the method acxxjrding to the~invention applied to the CMC7 character set. Each paragraph describing a flowchart block is preceded by the block number.

100. To determine the speed from the duration measured between two bars, it is necessary to know the threshold indicat¬ing whether this duration corresponds to a wide or a narrow space. For this purpose, for example, the dates of the last seven bars cire stored, i.e., the dates corresponding to the first char¬acter. Then, successive increasing threshold values are tried un¬til two wide spaces and four narrow spaces are detected. The found threshold enables to determine the speeds corresponding to the last six bars of the character, and the accelerations corre¬sponding to the last five bars of the character. The threshold is then more accurately adjusted as a function of the speed corre¬sponding to the last bar of the character. The threshold and the speed can be extrapolated from this last bar.
102. The system waits for the arrival of the first bar of the next character.
103. This first bar is dated.
104. The system waits for the next bar.
106. This next bar is dated, which determines the dura¬tion separating this bar from the preceding one.
108. The duration separating the two bars is compared with the predetermined threshold. If the duration is longer than the threshold, the speed is calculated by dividing the wide stan¬dardized distance by this duration, otherwise, the speed is cal¬culated by dividing the narrow standardized distance by this du¬ration. The acceleration can be adjusted as soon as two succes¬sive speeds are determined, i.e., upon the arrival of the third bar of the character. The threshold is adjusted with this new
SIDGGKX •
110. Between the arrivals of two bars, either two bars of a same character or the last and first bars of two successive characters, the speed and the threshold are extrapolated.
112. If necessary, the printing of a text on the cur¬rently processed check is synchronized from the speed directly determined in block 108 or extrapolated in block 110. More pre¬cisely, this speed is integrated by taking into account the ac^ celeration to estimate the distance traveled by the check, which

enables to know at which time a new vertical row of points should be printed.
114. If the bar is the last bar of the character, proc¬essing resumes at block 102 by waiting for the first bar of the next character. Otherwise, the processing continues at block 104 by waiting for the next bar of the character.
Fig. 4 schematically represents a read device according to the invention for 2-eading E13B control characters (Fig. 2) and determining the instantaneous travel speed of a check C that is manually drawn. This read device includes a read head 10 having two magnetic sensors A and B placed at a known distance d one from the other.
Each of sensors A and B is of the type conventionally used for reading magnetic ink characters and are both integrated, for example, in the same read head.
Fig. 5 represents an exemplary waveform of the signals provided by each of sensors A and B. If sensor A is the first sensor along the traveling direction of check C, represented by an arrow in Fig. 4, signal A is in phase advance with respect to signal B. This phase advance is inversely proportional to the travel speed of the check.
Signals A and B are sampled and stored. This is conven¬tionally done for a single signal in view of carrying out a shape recognition to identify the characters. According to the inven¬tion, to determine the travel speed at a sampling time t, a first approach consists of finding among the last samples of signal A a sample of same amplitude as that taken at time t for signal B. Then, the number of samples separating the sample of signal B from the sample of signal A provides, at time t, the time taken by the check to travel distance d, and thus the speed at time t.
This approach is sufficient assuming that the speed of check C does not vary along distance d.
A more accurate approach, taking into account the speed variations along distance d, consists of defining on signal B a portion SI constituted by the sample at time t and a few preced¬ing samples, then shifting this portion SI over time, running

through the last samples of signal A, uintil the minimuni distance between portion SI and a corresponding portion of signal A is ob¬tained. The shift of portion SI more accurately corresponds to the time taken by check C to travel distance d.
Of course, this method can be used only while signals A and B have amplitude variations. Thus, during the time intervals separating two characters, or even two pulses corresponding to a same character, the speed cannot be determined. The speed is then extrapolated as a function of the last determined speed and of the last calculated acceleration.
In order to recognize E13B control characters, each sample of signal B, for example, is stored with the corresponding speed. Then, the waveform of signal B is normalized, i.e., the waveform is locally expanded or compressed over time, using the corresponding samples and speeds, in order to produce the wave¬form that would have been obtained with a constant travel speed. This normalized waveform can then be subjected to a conventional shape recognition, which was already used to recognize the E13B characters.
" Fig. 6 represents an exemplary flowchart illustrating in more detail the method for determining the speed from E13B characters. A paracfraph describing a flowchart block is preceded by the block number.
200. It is checked whether the current sample of signal B exceeds a predetermined threshold. As mentioned above, the method for determining the speed cannot be used for portions where signals A and B are zero.
202. The sample of signal B exceeds the predetermined threshold. Then, as described above, the time interval separating the current sample of signal B from the best corresponding one among the last samples of signal A is determined.
204. The speed is calculated by dividing the distance d by the time interval determined at block 202. To allow an ex¬trapolation of the speed, the acceleration is also calculated from the last two speeds.

206. The sample of signal B does not exceed the prede¬termined threshold. Then, the speed is extrapolated from the last speed and acceleration values.
208. If necessary, the text printing on the check is synchronized from the determined or extrapolated speed. The wave¬form of signal B is normalized from speed information, to enable conventional shape recognition.
The processing resumes at block 200 with the next sam¬ple of signal B.
The method according to the invention can easily be im¬plemented by a suitably programmed microcontroler.
Having thus described at least one illustrative embodi¬ment of the invention, various alterations, modifications and im¬provements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be within the spirit and scope of the invention. Accordingly, the foregoing description is by way of example only and is not in¬tended to be limiting. The invention is limited only as defined in the following claims and the equivalents thereto.


WE CLAIM:
1. A device for determining the instantaneous travel speed of
documents having electronically exploitable control characters provided with bars
of standardized inter-spaces, comprising;
1. two sensors (A & B) placed at a predetermined distance (d) from one another for detecting the control characters, instantaneous speed being determined as a function of the passage duration of tAvo bars in front of the sensor and the speed separating said bars,
2. sampling means for sampling the respective signals from said sensors,
3. storing means for storing the samples of one of said sensors with the corresponding speeds,
4. sample means for sampling the signals from the second sensor B along the travel direction of said document,
5. finding means for finding a sample that corresponds best to the samples of the first sensor,
6. normalizing means for normalizmg the waveform of the signal output from one of said sensors with said samples and the corresponding speeds,
7. shape recognition means for applying shape recognition to said normalized waveform and
8. speed determining means for determining the instantaneous speed as a function of the distance separating the sensors and of the time distance separating said sample from the best corresponding sample.
2. The device for determining the instantaneous travel speed of
documents as claimed in claim 1, wherein said control characters have standard
patterns for shape recognition of the signal provided by said sensor.

3. A device for determining the instantaneous travel speed of documents substantially as herein described with reference to the accompanying drawings.


Documents:

0362-mas-1996 abstract.pdf

0362-mas-1996 claims.pdf

0362-mas-1996 correspondence -others.pdf

0362-mas-1996 correspondence -po.pdf

0362-mas-1996 description (complete).pdf

0362-mas-1996 drawings.pdf

0362-mas-1996 form-1.pdf

0362-mas-1996 form-26.pdf

0362-mas-1996 form-4.pdf

0362-mas-1996 form-9.pdf

0362-mas-1996 petition.pdf


Patent Number 192255
Indian Patent Application Number 362/MAS/1996
PG Journal Number 30/2009
Publication Date 24-Jul-2009
Grant Date 08-Nov-2004
Date of Filing 07-Mar-1996
Name of Patentee M/S. ASCOM MONETEL S A
Applicant Address RUE CLAUDE CHAPPE, 07500 GUILHERAND GRANGES
Inventors:
# Inventor's Name Inventor's Address
1 PATRICK BOISSONNET 7, RUE DE PROVENCE, 26800 PORTES-LESVALENCE
2 ANDRE CARABELLI QUATIER CHAVARAY, 07130 SAINT PERAY
PCT International Classification Number G04P 3/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA