JP2003040485A - Paper carrying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper carrying device capable of minimizing a detection margin of paper jam detection caused by temporary or elapsed carrying advance or delay of a carried paper to a paper carrying path changeover device which operates between carried papers forward and backward. SOLUTION: Detection control of a paper jam, which occurs when an interval of the carried paper becomes narrower than an operating time of a paper carrying path changeover mechanism part, is performed in addition to detection control of a paper jam, which is caused by the carrying advance or delay of the carried paper which possibly interferes the carried papers forward and backward. Thus, interference of the carried papers forward and backward each other caused by the temporal or elapsed carrying advance or delay does not occur, and furthermore when the carried paper is not caught by the paper carrying path changeover device, it is not determined as the paper jam and paper carrying is continued.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet conveying device for conveying a sheet (cut sheet) in a printing device or the like.

[0002]

2. Description of the Related Art In a sheet conveying apparatus, the movement of a sheet to be conveyed is controlled such as forming an image on one side or both sides and switching a sheet conveying path for discharging with the surface on which the image is formed facing upward or downward. It follows the control.

When a sheet is conveyed by a sheet conveying device for conveying cut sheets, the control unit manages the position of the conveyed sheet from the detection timing and the conveying speed of the leading edge and the trailing edge of the sheet conveyed by the sheet detecting sensor. is doing.

In the above-mentioned sheet conveying device, when a plurality of sheets are successively conveyed, the conveyed sheet may be advanced or delayed for some reason. When the conveyance advances or delays more than the sheet interval occur, the conveyance sheets interfere with each other to cause a paper jam. Therefore, the control apparatus constantly monitors the conveyance advance or the delay of the conveyance sheets.

As shown in FIG. 3 (a), it is ideal that two sheets of paper to be continuously conveyed are always conveyed at a constant interval of 1, but as shown in FIG. 3 (b) or (c), If the conveyance is advanced l ₁ or delayed l ₂ to the extent that they do not interfere with each other, it does not affect the paper transportation. Therefore, FIGS. 3 (b) and 3 (c)
If the advance or delay of the conveyance of the conveyed sheet shown in (1) is set as an allowable value, and if the conveyance of the conveyed sheet is advanced or delayed by the sheet detection sensor and the control unit, a paper jam is generated when the value exceeds the allowable value. Has become.

Here, a case where the sheet conveying path switching device is operated between the sheets 11 and 11 'will be described. As shown in FIG. 3 (d), when the operation of this paper transport path switching device requires a maximum time of lg, the distance between the papers 11 and 11 'must be wider than lg. The operation must be started after the trailing edge of the paper 11 has passed through the paper transport path switching device. That is, if the operation is started after the trailing edge of the sheet 11 has passed through the sheet transport path switching device and the operation is not finished before the leading edge of the sheet 11 ′ reaches the sheet transport path switching apparatus, the sheet transport path switching is performed. I pinched the transport paper in the device,
It causes a paper jam. Therefore, in order to continue the sheet conveyance even when the conveyance of the conveyed sheet is advanced or delayed, the allowable values of the sheet advance / delay are set to l ′ ₁ and l ′ ₂ as shown in FIG. Even when the advance / delay of the paper is maximized, the paper conveyance path switching device prevents the paper jam.

[0007]

However, changing the permissible values of the advance or delay of conveyance of conveyed sheets from l ₁ , l ₂ to l ′ ₁ , l ′ ₂ is as shown in FIGS. 3 (a) to 3 (c). As compared with the normal paper conveyance control shown, the paper jam detection margin for the advance or delay of the paper conveyance can be reduced. This is l on the upstream side of the paper transport path switching mechanism.
Sheets that have been conveyed with an advance or delay of ₁ or l ₂ being conveyed are l ′ ₁ and l ′ _{2 in the} sheet conveyance path switching mechanism section.
There is a problem in that the possibility of a paper jam increases due to the allowable value of the advance or delay of the conveyance, which leads to unnecessary paper jam.

The present invention solves such a problem. To provide a paper conveyance control method capable of minimizing a decrease in a paper jam detection margin in a paper conveyance path switching device in which a control timing is changed depending on whether the conveyance of a conveyed paper is temporarily or temporally advanced or delayed. Is.

[0009]

SUMMARY OF THE INVENTION A sheet conveying device according to the present invention is a sheet conveying path for sequentially conveying a plurality of sheets, a sheet conveying means for conveying sheets on the sheet conveying path, and the conveyed sheet is a sheet. A paper transport path switching device that operates at a predetermined time after reaching a predetermined position on the transport path or passing a predetermined position on the paper transport path, and a leading edge or a rear edge of the transport paper that is located upstream of the paper transport path switching device. The paper detection means for detecting the paper conveyance and the paper conveyance control means for operating the paper conveyance path switching device after a predetermined time has elapsed after the paper detection means detects the front end or the rear end of the paper In detecting a paper jam caused by exceeding l ₁ or the delay l ₂ , whether the distance between the conveyed papers in the paper detecting means is lg or more necessary for the operation of the paper conveying path switching device. By adding the control for judging, it is possible to minimize the reduction of the paper jam detection margin.

This will be described with reference to FIG. For comparison, the same time chart as in FIGS. 3A to 3E is shown in FIG.
(A) to (e) are shown.

As shown in FIGS. 5 (f) and 5 (g), the permissible value l of the advance or delay of the conveyance of the paper 11 and the paper 11 '.
_The paper is conveyed within the range of ₁ or l ₂ , and the paper 11 and the paper 1
If the interval of 1'is wider than the operation time lg of the paper transport path switching device, the paper is not jammed and the transport is continued.
It is possible to provide a sheet conveying apparatus and a control method thereof that can minimize the reduction of the sheet jam detection margin with respect to the normal sheet jam detection control shown in FIGS. 5A and 5B.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic configuration of a sheet transport path switching device of a sheet transport apparatus according to an embodiment of the present invention.

The sheet 11 conveyed from the upstream side is conveyed to the sheet conveying path 2 or the sheet conveying path 3 through the sheet conveying path 1. The paper transport path 1 is provided at a branch point of the paper transport paths 1 to 3.
There is a gate 6 for allocating the paper 11 conveyed above to the paper conveyance path 2 or the paper conveyance path 3, and rollers 7-9 for conveying the paper on the paper conveyance paths 1-3. Further, the paper detection sensor 4 is located at a position separated from the gate 6 by the length L on the upstream side of the paper transport path 1, and the paper detection sensor 5 is located further upstream from the paper detection sensor 4 at an appropriate distance. The paper detection sensors 4 and 5 are the paper 11
When the leading edge of the sheet 11 is detected, the off state is switched to the on state, and when the trailing edge of the sheet 11 is detected, the on state is switched to the off state. Here, the relationship between the roller 7 and the paper detection sensor 4 is not limited to that shown in FIG. 1, and the roller 7 may be between the paper detection sensor 4 and the gate 6.

FIG. 2 shows the structure of the control unit of the sheet conveying apparatus in this embodiment. The output signals of the paper detection sensors 4 and 5 are input to a control unit 10 composed of a CPU (central processing unit). According to the flow chart shown in FIG. 4, the rollers 7 to 9 of FIG. 1 and the driving units 12 to 15 of the gate 6 are controlled or a paper jam is detected.

Next, the operation of switching the sheet conveying path of the sheet conveying apparatus having the above structure will be described with reference to FIGS. When the leading edge of the sheet 11 conveyed from the upstream side reaches the sheet detection sensor 4, the output signal of the sheet detection sensor 4 changes from the off state to the on state. When the sheet 11 is conveyed to the sheet conveying path 2 as it is and the rear end reaches the sheet detecting sensor 4, the output signal of the sheet detecting sensor 4 changes from the ON state to the OFF state. At this time, when the sheet 11 ′ that is conveyed to the sheet conveying path 3 after the sheet 11 is conveyed, the gate 6 has the rear end of the sheet 11 passing through the gate 6 and then the front end of the sheet 11 ′ having the gate 6. It is necessary to perform the operation of switching from the paper transport path 2 to the paper transport path 3 before reaching the. Therefore, when the trailing edge of the paper 11 is detected by the paper detection sensor 4 (S1 in FIG. 4), the control unit 10 determines whether the paper detection sensor 4 advances or delays the conveyance of the paper 11, and determines whether the allowable value is satisfied. Make a decision (S
2). If the allowable value is exceeded, the paper 1 is detected as a paper jam.
When the roller that is transporting 1 is stopped (S11), but the allowable value is satisfied, it is determined whether the switching operation of the gate 6 is necessary to transport the paper 11 'following the paper 11 (S3), If necessary, time measurement is started after the trailing edge of the sheet 11 is detected by the sheet detection sensor 4 (S4).
When the time for the trailing edge of the sheet 11 to be conveyed from the sheet detection sensor 4 to the gate 6 has elapsed (S5), the switching operation of the sheet conveyance path of the gate 6 is started (S6). This gate 6
When the leading edge of the paper 11 ′ is detected by the paper detection sensor 4 during the time measurement until the start of the operation or after the switching operation of the gate 6 is started (S7), the control unit 10 advances the conveyance of the paper 11 ′ by the paper detection sensor 4. Alternatively, the delay is judged and it is judged whether the allowable value is satisfied (S8). When the allowable value is exceeded, the roller that is transporting the sheet 11 ′ is stopped as a paper jam (S11), but when the allowable value is satisfied, the distance l ′ between the trailing edge of the sheet 11 and the leading edge of the sheet 11 ′. '
Is the time l required for the operation of switching the sheet conveyance path of the gate 6.
It is judged whether it is sufficient by comparing with g (S9). l '' ≧ l
In the case of g, the conveyance is continued, but in the case of l ″ <lg (S12), the leading end of the paper 11 ′ reaches the gate 6 before the switching operation of the gate 6 is completed, and the paper 11
'Is likely to be caught in the gate 6, so the control unit 10
Stops the roller during conveyance of the sheet 11 'as a sheet jam (S11).

Here, in carrying out this control, the paper detection sensor 4 for detecting the leading end or the trailing end of the conveyed paper is shown in FIG.
Does not have to be the position. The paper detection sensor used for this control is best mounted at a point which should be the operation starting point of the gate 6 to be driven, but from the viewpoint of mounting or cost, the number of paper detection sensors is the minimum. It is desirable to do. Therefore, the paper detection sensor cannot always be mounted at the position shown in FIG. 1. Therefore, when the distance L between the gate 6 and the paper detection sensor 4 is sufficiently secured, the above control can be performed, but it is not so. In this case, the control can be performed by using the paper detection sensor 4 and the paper detection sensor 5 mounted at an appropriate and distant point upstream of the position of the paper detection sensor 4. That is, when the trailing edge of the sheet 11 cannot pass the operation of the gate 6 after the trailing edge of the sheet 11 passes through the sheet detecting sensor 4, the operation of the gate 6 starts when the trailing edge of the sheet 11 is detected by the sheet detecting sensor 5. The same control can be performed by changing the combination, such that the interval between the paper 11 and the paper 11 'is measured starting from the time when the paper passes and the output signal of the paper detection sensor 4 is used.

[0018]

As described above, according to the present invention,
For the paper transport path switching device that is controlled by following the progress or delay of the transport of the transport paper in the paper transport device,
It is possible to provide a sheet conveying device and a control method capable of minimizing the reduction of the sheet jam detection margin.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a sheet conveying device that is an embodiment of the present invention.

FIG. 2 is a block diagram of a control device of the paper transporting device that is an embodiment of the present invention.

FIG. 3 is a time chart of a conventional paper transport device.

FIG. 4 is a flow chart of a paper transporting device that is an embodiment of the present invention.

FIG. 5 is a time chart showing the operation of the present invention.

[Explanation of symbols]

1, 2, 3 ... Paper transport path, 4, 5 ... Paper detection sensor, 6
... Gates, 7, 8, 9 ... Paper transport rollers, 10 ... Control unit, 11 ... Transported paper, 12, 13, 14, 15 ... Rollers 7-9 and gate 6 drive unit.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H072 AA03 AA07 AA16 AA29 CA01                       CB01 EA01 JA02 JA04                 3F048 AA05 AB01 BA05 BB02 BB10                       CA04 CC03 CC04 CC17 DA06                       DB07 DB11 DC00 EA07 EB22                       EB30                 3F053 EA05 EC01 ED25 ED29 ED31                       LA06 LA07 LB03

Claims (2)

[Claims] 1. A conveyance roller, a sheet detection sensor for detecting the conveyed sheet, and a sheet conveyance path switching controlled by the timing when the leading edge of the sheet detection sensor is provided, in a sheet conveyance path of a printing apparatus for forming an image on a sheet. In a sheet conveying device equipped with a device, the sheet interval time is calculated from the trailing edge detection timing of continuously conveyed sheets and the leading edge detection timing of the next sheet, and the sheet interval time is switched by the sheet conveying path switching device. A paper conveyance device, which detects paper jam when the time required for operation is not satisfied. 2. A second sheet-feeding path upstream of the sheet-detecting sensor with respect to the sheet-transporting path switching device.
When the operation of the paper transport path switching device is not in time from the timing when the leading edge of the paper is reached by the paper detection sensor, the operation timing of the paper transport path switching device is determined by the second paper detection sensor. The sheet conveying apparatus according to claim 1, wherein the sheet conveying apparatus is a sheet conveying apparatus.