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Overlap detection apparatus and overlap detection methodOverlap detection apparatus and overlap detection method description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20070176355, Overlap detection apparatus and overlap detection method. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS REFERENCE TO RELATED APPLICATION [0001]This application claims priority from Japanese Patent Application No. 2006-21798, which is incorporated herein by reference. BACKGROUND OF THE INVENTION [0002]1. Field of the Invention [0003]The present invention relates to an overlap detection apparatus and an overlap detection method that are capable of detecting whether a sheet conveyed is a single or not. [0004]2. Related Art [0005]A hitherto known overlap detection apparatus, which includes a sheet conveying section for successively conveying sheets of paper (hereinafter referred simply to sheets), while each being displaced by a given amount from an upstream sheet in a conveying direction and overlapping the same, and a printing section for printing on sheets fed one by one from the sheet conveying section, includes a sheet detection sensor for detecting whether a sheet passing a given position is a single or not, a signal output section for outputting at periodic intervals overlapping signals that each take a first form (e.g., an H form) when the sensed sheet is a double or other multiple and each take a second form (e.g., an L form) when the sensed sheet is a single, and a determination section for determining on the basis of the detected result that sheets are being correctly conveyed while each being displaced by a given amount from an upstream sheet in the conveying direction and overlapping the same when an overlapping signal takes the second form and determining that the sheets are being not correctly conveyed when an overlapping signal takes the first form. The apparatus of this type is disclosed in Japanese Patent Application Laid-open No. Hei-11-180595. [0006]In the overlap detection apparatus of the type mentioned above, when sheets each are passing a given position, the sheet detection sensor detects whether each passing sheet is a single or not. Then, on the basis of the detected result of the sheet detection sensor, overlapping signals are output by the signal output section at given periodic intervals. [0007]The overlapping signals are output at given period intervals, such as periodic intervals at which single sheets are to pass a given position, and take a first form when sheets overlap each other and takes a second form when sheets do not overlap each other. [0008]The output overlapping signals are input into the determination section, which in turn determines that the sheets are being correctly conveyed for the second form and determines that the sheets are not being correctly conveyed for the first form. [0009]Thus, according to the conventional overlap detection apparatus, for example, overlapping signals are output at given periodical intervals, such as periodic intervals at which single sheets are to pass a given position, and when an overlapping signal takes the first form representative of that the sheet is a double or other multiple, the determination is made so that sheets are not being correctly conveyed. Whereby, a trouble in sheet feeding, such as a trouble of feeding multiple sheets to the printing section at a time, is detected. [0010]Such a sheet feeding trouble in a printing press is caused when a sheet passing the given position is a double or multiple at periodic intervals at which single sheets are to pass the given position, and sometimes caused when a sheet is displaced from an upstream sheet by an amount greater or small than a given amount in the sheet conveying direction and overlaps the same. In the latter case, a trouble of feeding double or multiple sheets to the printing section at a time or a trouble of feeding no sheet at a timing at which a sheet must be fed, may be caused. [0011]However, according to the conventional overlap detection apparatus, overlapping signals are output at given periodical intervals such as periodic intervals at which single sheets are to pass the given position. Therefore, even when a sheet is conveyed while being displaced from an upstream sheet by an amount greater or smaller than a given amount and overlapping the same and a non-overlapping portion (single sheet portion) of these sheets happens to pass the given position at a timing at which single sheets are to pass the given position following the given periodic intervals, an overlapping signal takes the second form (e.g., the L form). As a result, the determination section may determine that the sheets are being correctly conveyed even when it is not being correctly conveyed in the actual operation. [0012]It is an object of the present invention to provide an overlap detection apparatus and an overlap detection method that are capable of detecting a trouble in sheet feeding by determining whether or not sheets are being conveyed while each being displaced by a given amount from an upstream sheet in a sheet conveying direction and overlapping the same. SUMMARY OF THE INVENTION [0013]According to an aspect of the present invention, there is provided an overlap detection apparatus mounted to a printing press in which sheets are successively conveyed while each being displaced by a given amount from an upstream sheet in a sheet conveying direction and overlapping the same, including: 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 are being correctly conveyed while each being displaced by a given amount from an upstream sheet 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 are not being correctly conveyed when the portion of the overlapping signal taking the first form is not equal to the given reference portion. [0014]According to the overlap detection apparatus having the above arrangement, the sheet detection sensor detects whether a portion of the sheets passing the given position, which sheets being successively conveyed while each being displaced from an upstream sheet in the conveying direction and overlapping the same, is a non-overlapping portion or an overlapping portion. Then, the signal output section outputs an overlapping signal on the basis of the detected result of the sheet detection sensor, in which the overlapping signal takes the first form (e.g., an H form) for the overlapping portion (double sheet portion) and takes the second form (e.g., an L form) for the non-overlapping portion (single sheet portion). Then, the overlapping signal output from the signal output section is input to the determination section. [0015]Then, the determination section compares the portion of the overlapping signal taking the first form with the given reference portion, and when both the portions are equal to each other, it determines that the sheets are being correctly conveyed while each being displaced by a given amount from an upstream sheet in the conveying direction and overlapping the same, and when both are not equal, it determines that the sheets are not being correctly conveyed. [0016]According to another aspect of the present invention, there is provided an overlap detection apparatus mounted to a printing press in which sheets are successively conveyed while each being displaced by a given amount from an upstream sheet in a sheet conveying direction and overlapping the same, including: 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; and a determination section for determining that the sheets are being correctly conveyed while each being displaced by a given amount from an upstream sheet 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 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. [0017]According to the overlap detection apparatus having the above arrangement, the sheet detection sensor detects whether a portion of the sheets passing the given position, which sheets being successively conveyed while each being displaced from an upstream sheet in the conveying direction and overlapping the same, is a non-overlapping portion or an overlapping portion. Then, the signal output section outputs an overlapping signal on the basis of the detected result of the sheet detection sensor, in which the overlapping signal takes the first form (e.g., an H form) for the overlapping portion (double sheet portion) and takes the second form (e.g., an L form) for the non-overlapping portion (single sheet portion). Then, the overlapping signal output from the signal output section is input to the determination section. [0018]Then, the determination section compares 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, with the given reference timing, and when both the timings are equal to each other, it determines that the sheets are being correctly conveyed while each being displaced by a given amount from an upstream sheet in the conveying direction and overlapping the same, and when both are not equal, it determines that the sheets are not being correctly conveyed. [0019]In the above overlap detection apparatus, the printing press preferably 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. [0020]It is preferable to employ an arrangement, in which the printing press includes a feeder board that conveys the sheets 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. [0021]It is preferable that the overlapping signal takes an H form for the overlapping sheet portion and takes an L form for the non-overlapping portion. Continue reading about Overlap detection apparatus and overlap detection method... Full patent description for Overlap detection apparatus and overlap detection method Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Overlap detection apparatus and overlap detection method patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Overlap detection apparatus and overlap detection method or other areas of interest. ### Previous Patent Application: Image forming device Next Patent Application: Rules engine for mailpiece content modification Industry Class: Sheet feeding or delivering ### FreshPatents.com Support Thank you for viewing the Overlap detection apparatus and overlap detection method patent info. 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