JP4614215B2 - Sheet jam detection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention can easily be prepared by treating the sheet that caused the jam, when discharging the remaining sheets in the sheet conveying path, relates sheet jam detecting apparatus adapted to discharge while checking the transport of each sheet is there.
[0002]
[Prior art]
Conventionally, there is a device described in Japanese Utility Model Publication No. 53-26984 as a jam detection device. This jam detection device is provided with a plurality of detectors that detect the passage of a sheet at an appropriate position in the path along which the sheet is conveyed, and the conveyance of the sheet from the detector to the next detector sequentially passes. Is measured by a timer, and if it does not pass within a predetermined time, it is determined that a jam has occurred.
[0003]
[Problems to be solved by the invention]
Incidentally, in an apparatus such as a high-speed printer and a copying machine, a plurality of sheets exist on the sheet conveyance path of the apparatus when performing continuous printing (or copying). In this case, when a jam occurs as described above, the sheet on the sheet conveying path is stopped when the jam occurs, and the passage of the sheet cannot be measured, and the detection of the sheet starts from the time when the sheet stops. For this reason, it is difficult to accurately check the conveyance of the sheet after removing the jam and the sheet causing the jam (hereinafter referred to as “jam sheet”).
[0004]
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a jam detection device that can reliably detect a jam sheet and a sheet remaining on the conveyance path by the jam.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention provides one or more detection means provided at appropriate positions in the sheet conveyance path for detecting the passage of the conveyed sheet, and one or each of the detection means. One or more cover members disposed on the cover member, detection means provided on each of the cover members, control means for determining a sheet conveyance state based on detection results of the detection results and detection results of the detection means, The detection means includes a first count unit that counts that the leading edge of the sheet has passed, a second count unit that counts that the trailing edge of the sheet has passed, and discharge of the sheet after processing of sheet jamming. A third counting unit that counts that the leading edge of the sheet has passed when performing the sheet and a fourth counting unit that counts that the trailing edge of the sheet has passed when the sheet is discharged after the sheet jamming process. And When the sheet is normally conveyed, the control unit includes a first count unit of the detection unit, a first count unit of the next detection unit, a second count unit of the detection unit, and a second count of the next detection unit. The control unit determines that the sheet is not conveyed, the control unit is in a state where the sheet is not conveyed, the cover member is opened, and the sheet that causes the sheet is processed and remains on the sheet conveying path. When discharging an arbitrary sheet, when detecting the opening of an arbitrary cover member, the third counting unit and the fourth counting unit in the opened area are counted, and the first counting unit of the detecting means The sum of the third counting part of the detection means and the sum of the first count part of the next detection means and the third count part of the next detection means are compared, and the second count part of the detection means and the detection means The fourth count of And the sum of the second count unit of the next detection unit and the fourth count unit of the next detection unit to determine the sheet conveyance state, and the control unit further conveys the sheet In the case where the cover member is opened and the sheet that does not cause the processing is processed and the sheet remaining on the sheet conveyance path is discharged, based on the detection result other than the detection means in the opened area The sheet conveyance state is determined . Further, the conveyance path includes a sheet discharge unit from the sheet supply unit.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings. FIG. 1 shows an outline of a sheet jam detection device applied to the present invention. This sheet jam detection device includes a sheet conveying path 10 that conveys a sheet to a predetermined place, and detection means Sn (provided at one or more appropriate positions in the sheet conveying path 10) that detects the passage of the conveyed sheet Pn (however, N ≧ 1) and one or more cover members An provided between the detection means Sn or between the detection means Sn and the detection results of the detection means Sn and the detection means Dn. Control means 20 for checking the conveyance of the sheet Pn.
[0010]
The detection unit Sn includes a count unit Cn, and is a microswitch, a photo interrupter, a reflection type sensor, or the like, and is connected to the control unit 20. Further, the count unit Cn includes a first count unit Cn1 that counts that the leading end of the sheet Pn has passed, a second count unit Cn2 that counts that the trailing end of the sheet Pn has passed, and after jamming of the sheet P The third count unit Cn3 that counts that the leading edge of the sheet Pn has passed when discharging the sheet Pn, and that the trailing edge of the sheet Pn has passed when discharging the sheet Pn after jamming of the sheet Pn. And a fourth count unit Cn4 for counting.
[0011]
The cover member An is disposed on one of the detection means or between the detection means on the sheet conveyance path. The detection means Dn is provided in each cover member An. Each detecting means Dn detects the operation when the sheet is not conveyed at a predetermined timing, for example, when a jam occurs, and when the cover member An located on the sheet causing the sheet is opened. It is configured. In this embodiment, the detection means Dn is a microswitch, a photo interrupter, a reflection type sensor or the like, like the detection means Sn. The detection means Dn is connected to the control means 20 similarly to the detection means Sn.
[0012]
FIG. 2 shows an outline of the control means 20. The control means 20 includes a CPU 21 for checking the conveyance of the sheet Pn, a ROM 22 in which a program for checking the conveyance of the sheet Pn is written, and a RAM 23 for temporarily storing the detection results of the detection means Sn and the detection means Dn. A timer 24 for measuring the operation time of the sheet jam detection device is provided. The detection means Sn and the detection means Dn are connected via the interface 25.
[0013]
FIG. 3 shows a flowchart for performing a conveyance check of the sheet conveyance path 10 in the present invention. When printing is started, the sheets Pn are continuously conveyed on the sheet conveying path 10 as shown in FIG. The detection means Sn detects the sheet Pn that has passed and sends the detection result to the control means 20. At this time, the first count unit Cn1 counts one when the leading end of the sheet Pn passes, and the second count unit Cn2 counts one when the trailing end of the sheet Pn passes (step 1).
[0014]
Next, it is determined whether a jam has occurred (step 2). In this step, the jam is determined based on whether or not the count number of the first count unit Cn1 and the count number of the second count unit Cn2 are the same. If these count numbers are the same, the control means 20 determines that there is no jam and the jam detection ends. On the contrary, if these count numbers are different, it is determined that a jam has occurred, and the process proceeds to a process for stopping the sheet conveyance path 10 for the jam (step 3).
[0015]
When the jam of the sheet conveyance path 10 is confirmed in step 2, the control unit 20 stops the conveyance of the sheet Pn, and outputs the confirmed occurrence position of the jam to a display unit (not shown) to the user. Inform. For example, FIG. 4 shows the count state of each detection means Sn in FIG. In FIG. 1, the arrow direction is the conveyance direction of the sheet Pn. When a certain sheet P1 (here, the head) is jammed, the difference in the count that has passed the leading edge of the sheet Pn is two between C11 and C21, and three between C21 and C31. The difference in the count that has passed through the rear end of Pn is two sheets between C12 and C22, two between C22 and C32, and the sheet Pn that is not detected between the detection means (S11 to S13). I can know. This count number is used when a conveyance check of the sheet conveyance path 10 described later is performed. When the user removes the jam sheet P1, the detection means Dn (here, the third detection means S3) provided in the removed area detects this and sends the detection result to the control means 20. At this time, the third count portion Cn3 and the fourth count portion Cn4 provided in each detection means Sn are set so that the leading edge and the trailing edge of the sheet Pn can be counted. At this time, the count numbers of the third count unit Cn3 and the fourth count unit Cn4 are zero.
[0016]
When the detection unit D3 detects that, that is, when the processing of the jammed sheet P1 is completed, the control unit 20 performs conveyance check on the sheet conveyance path (step 6). This step is performed by each of the count units Cn1 and Cn2 described above, and the third count unit Cn3 and the fourth count unit Cn4 corresponding thereto. The third count unit Cn3 and the fourth count unit Cn4 are counted in increments of 1 from the time when the sheet Pn stops. For example, after performing jam processing in FIG. 4, the sheet Pn is conveyed again. In this state, the last part of the sheet P7 is the end of conveyance.
[0017]
In this state, first, the detection means S1 and the second detection means S2 are compared. More specifically, the sum of the counts passed by the leading edge of the sheet Pn, that is, the sum of C11 and C13, and the sum of C21 and C23 are compared. Further, the sum of the counts passed through the trailing edge of the sheet Pn, that is, the sum of C12 and C14 is compared with the sum of C22 and C24. If the sums are different at this time, it is determined that a jam has occurred in the detection means S1n, and the process returns to step 4. If each sum is equal, it is determined that the sheet Pn is normally conveyed (sheet Pn is discharged), and sequentially compared with the sum of CN21 and CN23 and the sum of CN31 and CN33. The sum of CN22 and CN24 and the sum of CN32 and CN34 are compared (compare the second detection means S2 and the third detection means S3), and if the sum is different, return to step 4 (step 7).
[0018]
When the user removes the jam sheet P1 and the other sheets Pn, for example, in FIG. 1, the sheet in the detection means Dn (here, the second detection means S2) provided in another area is removed. Thus, the case where the detection unit D2 detects that the jam has been processed will be described. In this state, if step 4 is executed, the count numbers of the respective counting units Cn in the second detection means S2 and the third detection means S3 will not match. For this reason, when it is estimated that the detection result of the detection means Dn has removed the sheet Pn other than the jam sheet, the control means 20 ignores the detection result between the detection means Sn (here, between S2 and S3). Step 6 is performed.
[0019]
In this way, when the leading edge / rear edge of the sheet that has passed is counted, a jam occurs, this is dealt with, and when the sheet is detected from the time it stopped, it is between the detecting means Sn and the next detecting means It is possible to detect the sheets (P1, P2, P3, P4, and P6) that are not detected by Sn + 1 and reliably carry the sheet after the jam processing.
[0020]
【The invention's effect】
As described above, it is possible to reliably detect a jam on the sheet conveyance path and process a sheet remaining on the sheet conveyance path regardless of the print processing capability, the length of the sheet conveyance path, and the size of the sheet. .
[Brief description of the drawings]
FIG. 1 is a diagram showing an outline of a sheet jam detection device applied to the present invention.
FIG. 2 is a diagram showing an outline of control means.
FIG. 3 is a flowchart illustrating a conveyance check.
FIG. 4 is a diagram illustrating a conveyance check state of each detection unit.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Sheet conveyance path 20 Control means Pn Sheet Sn detection means Dn Detection means Cn Count part An Cover member

Claims (2)

One or more detection means provided at appropriate locations on the sheet conveyance path for detecting passage of the conveyed sheet, and one or more cover members disposed between one of the detection means or each of the detection means, Detecting means provided on each cover member, and control means for determining the sheet conveyance state based on the detection result of the detection result and the detection result of the detection means,
The detection means includes a first count unit that counts that the leading end of the sheet has passed, a second count unit that counts that the trailing end of the sheet has passed, and discharges the sheet after processing of sheet jamming. A third counting unit that counts that the leading edge of the sheet has passed when performing, and a fourth counting unit that counts that the trailing edge of the sheet has passed when discharging the sheet after processing of sheet jamming Have
When the sheet is normally conveyed, the control means includes a first count section of the detection means, a first count section of the next detection means, a second count section of the detection means, and the next The second count unit of the detection means is compared with each other to determine the conveyance state of the sheet,
In addition, the control unit may be in any state when the sheet is not conveyed, the cover member is opened, the sheet causing the sheet is processed, and the sheet remaining on the sheet conveyance path is discharged. When detecting the opening of the cover member, the third counting unit and the fourth counting unit in the opened area are counted, and the first counting unit of the detecting unit and the third counting unit of the detecting unit And the sum of the first count part of the next detection means and the third count part of the next detection means, and the second count part of the detection means and the fourth count of the detection means And the sum of the second count unit of the next detection unit and the fourth count unit of the next detection unit to determine the conveyance state of the sheet,
Further, the control means opens the cover member when the sheet is not conveyed, the cover member is opened, the non-causing sheet is processed, and the sheet remaining on the sheet conveyance path is discharged. A sheet jam detection apparatus that determines a conveyance state of the sheet based on a detection result other than the detection unit in the area .   The sheet jam detection device according to claim 1, wherein the conveyance path includes a sheet discharge unit from a sheet supply unit.

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