Patent US3706867A successfully refreshed from Google Patents.
Patent EP0206675A2 successfully refreshed from Google Patents.
EP0206675A2
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EP
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Monitoring sheet length
Assignee: De la Rue Systems Ltd
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Filing: 1986-06-12
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Granted: —
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Expires: 2006-06-12
Abstract
Abstract A method and apparatus for monitoring the length of sheets, such as banknotes, passing a predetermined position is described. The apparatus includes two pairs of rollers 1, 2 defining respective nips 5, 6 through which a sheet passes. The passage of a sheet causes radial movement of portions 11 of the rollers 2 which is detected by detectors 12 mounted in a shaft 4. The passage of a sheet causes respective counters 15, 16 to be incremented at a relatively fast sheet. The method comprises 1) monitoring a relatively fast rate count at least in two pairs of intervals wherein a) during one interval of each pair leading and trailing edges of the sheet are sensed respectively, the count being monitored for a period during the interval related to the time at which the leading or trailing edge passes the predetermined position, and during the other interval of each pair the count is monitored for the entire interval, b) during each interval the count is incremented at a constant rate, and c) the duration of the intervals is long compared with the time between successive counts; 2) determining respective total counts from the monitored counts; 3) determining first and second values related to the lengths of the portions of the sheet passing the predetermined position during the intervals in which the leading and trailing edges are sensed by comparing the total counts monitored in the intervals of each pair; 4) determining a third value related to the length of the portion of the sheet passing the predetermined position between the intervals in which the leading and trailing edges are sensed; and 5) deriving a value related to the total length of the sheet passing the predetermined position from the first, second, and third values.
Inventors
- 👤 David Robert Worsley
- 👤 Trevor James Conner
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 11:26
CPC Classifications
G; G07; G07D; G07D7/00; G07D7/16; G07D7/162; G01; G01B; G01B21/00; G01B21/02; G01B21/06
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
225 words
A method of monitoring the length of sheets passing a predetermined position, the method comprising 1) monitoring a relatively fast rate count at least in two pairs of intervals wherein a) during one interval of each pair leading . and trailing edges of the sheet are sensed respectively, the count being monitored for a period during the interval related to the time at which the leading or trailing edge passes the predetermined position, and during the other interval of each pair the count is monitored for the entire interval, b) during each interval the count is incremented at a constant rate, and c) the duration of the intervals is long compared with the time between successive counts; 2) determining respective total counts from the monitored counts; 3) determining first and second values related to the lengths of the portions of the sheet passing the predetermined position during the intervals in which the leading and trailing edges are sensed by comparing the total counts monitored in the intervals of each pair; 4) determining a third value related to the length of the portion of the sheet passing the predetermined position between the intervals in which the leading and trailing edges are sensed; and 5) deriving a value related to the total length of the sheet passing the predetermined position from the first, second, and third values.
Claim 2
Independent Claim
225 words
A method of monitoring the length of sheets passing a predetermined position, the method comprising 1) monitoring a relatively fast rate count at least in two pairs of intervals wherein a) during one interval of each pair leading . and trailing edges of the sheet are sensed respectively, the count being monitored for a period during the interval related to the time at which the leading or trailing edge passes the predetermined position, and during the other interval of each pair the count is monitored for the entire interval, b) during each interval the count is incremented at a constant rate, and c) the duration of the intervals is long compared with the time between successive counts; 2) determining respective total counts from the monitored counts; 3) determining first and second values related to the lengths of the portions of the sheet passing the predetermined position during the intervals in which the leading and trailing edges are sensed by comparing the total counts monitored in the intervals of each pair; 4) determining a third value related to the length of the portion of the sheet passing the predetermined position between the intervals in which the leading and trailing edges are sensed; and 5) deriving a value related to the total length of the sheet passing the predetermined position from the first, second, and third values.
Claim 3
Dependent Claim
29 words
A method according to claim 1, wherein step 4 comprises determining the number of intervals during which the sheet moves through substantially the same distance past the predetermined position.
Claim 4
Dependent Claim
23 words
A method according to claim 1 or claim 2, wherein the two pairs of intervals are separated by ten to twenty different intervals.
Claim 5
Independent Claim
24 words
A method according to any of the preceding claims, wherein the count is monitored only when a sheet is sensed at the predetermined position.
Claim 6
Dependent Claim
31 words
A method according to claim 4, wherein the count is initiated at least when a leading edge of the sheet is sensed and is stopped when a trailing edge is sensed.
Claim 7
Independent Claim
41 words
A method according to any of the preceding claims, wherein step 1 includes the step of monitoring the rotation of a shaft of transport means controlling movement of the sheets, and generating a timing signal after equal rotations of the shaft.
Claim 8
Independent Claim
25 words
A method according to any of the preceding claims, wherein step 5 comprises summing the first, second and third values to generate the fourth value.
Claim 9
Independent Claim
21 words
A method according to any of the preceding claims, wherein there are about 30 fast rate count pulses in each interval.
Claim 10
Independent Claim
33 words
A method according to any of the preceding claims, further comprising carrying out steps 1-5 at two predetermined postions laterally offset from one another relatively to the direction of movement of the sheets.
Claim 11
Dependent Claim
85 words
Apparatus for monitoring the length of sheets passing a predetermined position, the apparatus comprising transport means for transporting the sheets past the predetermined position; sensing means for sensing the presence of a sheet at the predetermined postion; a counter which may be incremented at a relatively fast rate; processing means for carrying out steps 1 to 5 of a method according to any of the preceding claims; and comparison means for comparing the determined length with a reference and for providing a corresponding output signal.
Claim 12
Dependent Claim
59 words
Apparatus according to claim 10, wherein the transport means includes a shaft which is rotatable to control movement of the sheets, the sensing means comprising a slotted timing disc non-rotatably mounted to the shaft and detection means fixed relatively to the timing disc for sensing the movement of slots past the sensing means and for generating suitable output signals.
Claim 13
Dependent Claim
17 words
Apparatus according to claim 11, wherein the output signals generated by the detection means zero the counter.
Claim 14
Dependent Claim
38 words
Apparatus according to any of claims 10 to 12, wherein the counter is enabled by the sensing means when the leading edge of a sheet is sensed and disabled when the trailing edge of a sheet is sensed.
Claim 15
Independent Claim
39 words
A system for monitoring the length of sheets passing two laterally spaced positions, the system comprising two sets of apparatus according to any of claims 10 to 13, the processing means and comparison means being common to both apparatus.
Claim 16
Independent Claim
100 words
A method of detecting the acceptability of sheets comprising a) monitoring the length of a sheet at two laterally spaced positions; b) determining the difference between the monitored lengths; c) comparing the difference with a predetermined threshold to determine whether the difference is large or small; d) i) if the difference is large, comparing each monitored length with predetermined reference values to determine the acceptability of the sheet; or ii) if the difference is small, determining the average of the two lengths, and comparing the average with one or more predetermined reference values to determine the acceptability of the sheet.
Claim 17
Independent Claim
100 words
A method of detecting the acceptability of sheets comprising a) monitoring the length of a sheet at two laterally spaced positions; b) determining the difference between the monitored lengths; c) comparing the difference with a predetermined threshold to determine whether the difference is large or small; d) i) if the difference is large, comparing each monitored length with predetermined reference values to determine the acceptability of the sheet; or ii) if the difference is small, determining the average of the two lengths, and comparing the average with one or more predetermined reference values to determine the acceptability of the sheet.
Claim 18
Dependent Claim
19 words
A method according to claim 15, further comprising generating a signal in accordance with the determination of step d.
Claim 19
Dependent Claim
26 words
A method according to claim 15 or claim 16, wherein step d(i) determines a sheet to be acceptable if one of the monitored lengths is acceptable.
Claim 20
Independent Claim
23 words
A method according to any of claims 15 to 17, wherein the reference values comprise a pair of maximum and minimum length values.
Claim 21
Dependent Claim
39 words
A method according to claim 18, when dependent on claim 17, wherein step d(i) comprises determining a sheet to be acceptable if one of the monitored lengths lies in the range defined by the maximum and minimum length values.
Claim 22
Dependent Claim
34 words
A method according to claim 18 or claim 19, wherein step d(ii) comprises determining a sheet to be acceptable if the average lies in the range defined by the maximum and minimum length values.
Claim 23
Dependent Claim
20 words
A method according to any of claims 15 to 20, wherein step a comprises a method according to claim 9.
Claim 24
Independent Claim
16 words
A method of monitoring the length of banknotes according to any of claims 1 to 9.
References Cited (Backward Citations)
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