Claims
- 1. In an inserter including means for conveying inserts, a skew detector arrangement for detecting and measuring skew misalignement of inserts while said inserts are being conveyed by said means for conveying along an insert conveying path, said skew detector arrangement comprising:
- a plurality of retroreflective targets disposed relative to said means for conveying;
- a plurality of photosensors directed toward said plurality of retroreflective targets, said photosensors including a light source for directing light beams toward said retroreflective targets, wherein inserts being conveyed by said means for conveying pass between said targets and said photosensors to obstruct the retroreflective view of said photosensors;
- said photosensors being adapted to produce signals in response to changes in said retroreflective view;
- means for sampling said signals provided by individual said photosensors in synchronous timing in relation to the conveying motion of inserts on said means for conveying to provide obstruction signals as measures of relative obstruction by inserts of said plurality of targets;
- means for evaluating and modulating said obstruction signals in dependence on insert conveying speed to provide evaluated signals;
- means for preprogramming pre-established rejection thresholds for skew and misalignment of inserts, said means for preprogramming including means for varying the rejection thresholds in dependence on insert conveying speed;
- means for comparing the evaluated signals with the rejection thresholds and for providing skew and misalignment rejection signals in response to said comparing; and,
- means for diverting away from said insert conveying path respective inserts as a consequence of said skew and misalignment rejection signals.
- 2. The skew detector arrangement according to claim 1, wherein individual ones of said plurality of photosensors are directed at and view those individual ones of said plurality of targets that are disposed in corresponding locations, and wherein said means for evaluating and modulating and said means for comparing include means for discriminating the relative incidence timing of the obstruction between said individual targets by inserts being conveyed.
- 3. The skew detector arrangement of claim 2, wherein said means for sampling includes means for detecting leading and trailing edges of inserts.
- 4. The skew detector according to claim 1, wherein said inserter includes at least one insert feeder for dispensing inserts to said means for conveying, said skew detector being disposed along said means for conveying downstream from said at least one insert feeder.
- 5. A method of detecting skew and misalignment of inserts in an inserter, the method comprising steps of:
- conveying inserts between a plurality of retroreflective targets and a plurality of photosensors that are disposed relative to the conveying motion;
- directing light beams from said photosensors toward said retroreflective targets;
- sensing obstruction of said targets by conveyed inserts, said sensing being effected by said photosensors;
- providing signals in response to said obstruction;
- sampling said signals provided by individual said photosensors in synchronous timing relation to the conveying motion of inserts and providing obstruction signals as measures of relative obstruction by inserts of said plurality of targets;
- evaluating and modulating said obstruction signals in dependence on insert conveying speed and providing evaluated signals;
- preprogramming pre-established rejection thresholds for skew and misalignment of inserts and varying the rejection thresholds in dependence on insert conveying speed;
- comparing the evaluated signals with the rejection thresholds and providing skew and misalignment rejection signals in accordance with such comparison; and,
- diverting inserts away from the normal insert conveying path as a consequence of said skew and misalignment rejection signals.
- 6. The method according to claim 5, wherein individual ones of said plurality of photosensors are directed at and view corresponding targets, and wherein said steps of evaluating and modulating and said step of comparing include a step of discriminating the relative transverse incidence timing of the obstruction between said individual targets by inserts being conveyed thereover.
- 7. The method of claim 6, wherein said step of sampling includes detecting the leading and trailing edges of inserts.
Parent Case Info
This is a division of application Ser. No. 07/338,171, filed Apr. 14, 1989, now U.S. Pat. No. 5,029,832.
US Referenced Citations (19)
Foreign Referenced Citations (4)
Number |
Date |
Country |
0102700 |
Mar 1984 |
EPX |
2543491 |
Mar 1984 |
FRX |
1237873 |
Jun 1971 |
GBX |
1567603 |
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GBX |
Divisions (1)
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Number |
Date |
Country |
Parent |
338171 |
Apr 1989 |
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