Overlap detection apparatus and overlap detection method

Abstract

An overlap detection apparatus mounted to a printing press includes a sheet detection sensor for detecting whether a portion of the sheets passing a given position is a non-overlapping portion or an overlapping portion; a signal output section for outputting an overlapping signal on the basis of the detected results of the sheet detection sensor, in which the overlapping signal takes a first form for the overlapping portion and takes a second form for the non-overlapping portion; and a determination section for determining that the sheets of paper are being correctly conveyed while each being displaced by a given amount from an upstream sheet of paper in the conveying direction and overlapping the same when a portion of the overlapping signal taking the first form is equal to a given reference portion, and determines that the sheets of paper are not being correctly conveyed when the portion of the overlapping signal taking the first form is not equal to the given reference portion.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The above, and other objects, features and advantages of the present invention will become apparent from the detailed description thereof in conjunction with the accompanying drawings wherein.

FIG. 1 is a schematic view of a pat of a printing press equipped with an overlap detection apparatus according to a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating a control method of the overlap detection apparatus of the first embodiment.

FIG. 3 is a schematic view of a pat of a printing press equipped with an overlap detection apparatus according to a second embodiment of the present invention.

FIG. 4 is a flowchart illustrating a control method of the overlap detection apparatus of the second embodiment.

Claims

1. An overlap detection apparatus mounted to a printing press in which sheets of paper are successively conveyed while each being displaced by a given amount from an upstream sheet of paper in a sheet conveying direction and overlapping the same, comprising: a sheet detection sensor for detecting whether a portion of the sheets passing a given position is a non-overlapping portion or an overlapping portion;a signal output section for outputting an overlapping signal on the basis of the detected results of the sheet detection sensor, in which the overlapping signal takes a first form for the overlapping portion and takes a second form for the non-overlapping portion; anda determination section for determining that the sheets of paper are being correctly conveyed while each being displaced by a given amount from an upstream sheet of paper in the conveying direction and overlapping the same when a portion of the overlapping signal taking the first form is equal to a given reference portion, and determines that the sheets of paper are not being correctly conveyed when the portion of the overlapping signal taking the first form is not equal to the given reference portion.

2. An overlap detection apparatus mounted to a printing press in which sheets of paper are successively conveyed while each being displaced by a given amount from an upstream sheet of paper in a sheet conveying direction and overlapping the same, comprising: a sheet detection sensor for detecting whether a portion of the sheets passing a given position is a non-overlapping portion or an overlapping portion;a signal output section for outputting an overlapping signal on the basis of the detected result of the sheet detection sensor, in which the overlapping signal takes a first form for the overlapping portion and takes a second form for the non-overlapping portion; anda determination section for determining that the sheets of paper are being correctly conveyed while each being displaced by a given amount from an upstream sheet of paper in the conveying direction and overlapping the same, when the timing, at which the form of the overlapping signal is changed from the first form to the second form or vice versa, relative to a printing reference of the printing press, is equal to a given reference timing; and determines that the sheets of paper are not being correctly conveyed, when the timing, at which the form of the overlapping signal is changed from the first form to the second form or vice versa, relative to the printing reference of the printing press, is not equal to the given reference timing.

3. The overlap detection apparatus according to claim 2, wherein the printing press includes a sheet feeding cylinder, and an encoder that outputs a rotation signal with reference to the rotation of the sheet feeding cylinder, and the rotation signal output by the encoder is employed as the printing reference of the printing press.

4. The overlap detection apparatus according to any one of claims 1 and 2, wherein the printing press includes a feeder board that conveys the sheets of paper placed thereon towards a downstream side; the sheet detection sensor comprises a pair of upper and lower members disposed vertically with a downstream end of the feeder board therebetween so as to detect whether a portion of the sheets passing between the upper and lower members of the sheet detection sensor is the non-overlapping portion or the overlapping portion.

5. The overlap detection apparatus according to any one of claims 1 and 2, wherein the overlapping signal takes an H form for the overlapping sheet portion and takes an L form for the non-overlapping portion.

6. The overlap detection apparatus according to any one of claims 1 and 2, wherein the printing press includes a feeder board that conveys the sheets of paper placed thereon towards a downstream side; the determination section outputs a stop signal when it determines that the sheets of paper are not being correctly conveyed; and the printing press further includes a feeder board stop device that stops the feeder board on the basis of the stop signal.

7. The overlap detection apparatus according to any one of claims 1 and 2, wherein the printing press includes a feeder board that conveys the sheets of paper placed thereon towards a downstream side; and the determination section outputs an annunciation signal when it determines that the sheets of paper are not being correctly conveyed; and the printing press further includes an annunciation device that is actuated on the basis of the annunciation signal.

8. The overlap detection apparatus according to any one of claims 1 and 2, wherein the signal output section comprises an amplifier.

9. An overlap detection method of determining whether or not sheets of paper are being correctly conveyed in a printing press, in which the sheets of paper are conveyed while each being displaced by a given amount from an upstream sheet of paper in a sheet conveying direction and overlapping the same, on the basis of detection of an overlapping state of the sheets of paper, comprising: detecting whether a portion of the sheets passing a given position is a non-overlapping portion or an overlapping portion by a sheet detection sensor;outputting an overlapping signal on the basis of the detected result of the sheet detection sensor, in which the overlapping signal takes a first form for the overlapping portion; anddetermining that the sheets of paper are being correctly conveyed while each being displaced by a given amount from an upstream sheet of paper in the conveying direction and overlapping the same when a portion of the overlapping signal taking the first form is equal to a given reference portion, and determining that the sheets of paper are not being correctly conveyed when the portion of the overlapping signal taking the first form is not equal to the given reference portion.

10. An overlap detection method of determining whether or not sheets of paper are being correctly conveyed in a printing press, in which the sheets of paper are conveyed while each being displaced by a given amount from an upstream sheet of paper in a sheet conveying direction and overlapping the same, on the basis of detection of an overlapping state of the sheets of paper, comprising: detecting whether a portion of the sheets passing a given position is a non-overlapping portion or an overlapping portion by a sheet detection sensor;outputting an overlapping signal on the basis of the detected result of the sheet detection sensor, in which the overlapping signal takes a first form for the overlapping portion and takes a second form for the non-overlapping portion; anddetermining that the sheets of paper are being correctly conveyed while each being displaced by a given amount from an upstream sheet of paper in the conveying direction and overlapping the same when the timing, at which the form of the overlapping signal is changed from the first form to the second form or vice versa, relative to a printing reference of the printing press, is equal to a given reference timing, and determining that the sheets of paper are not being correctly conveyed when the timing, at which the form of the overlapping signal is changed from the first form to the second form or vice versa, relative to the printing reference of the printing press, is not equal to the given reference timing.