JPH036574A - Paper feeding controller - Google Patents

Abstract

PURPOSE:To control paper feeding intervals properly by stopping a paper feeding means temporarily in response to the detection of the front edge of a next form by a form detecting means and operating a paper feeding means in response to the output of a measuring means. CONSTITUTION:Forms which are fed out of form storage parts 12 14 are stopped when their head edges are detected by form detecting means 24 - 26 and the forms begin to be supplied at the positions. The supplied forms, therefore, begin to be supplied at the fixed positions at all times. Further, a measuring means 361 feeds next forms after a time corresponding to the necessary irreducible form interval. Therefore, the form intervals are shortened to less than a desired interval and forms are prevented from colliding against each other and jamming. Consequently, excellent paper feeding control becomes possible.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a paper feed control device applied to copying machines, printing machines, etc. The present invention relates to an improvement of a paper feed control device that can perform the following steps.

<Prior Art> For example, a copying machine is equipped with a paper feed control device that feeds sheets of paper stored in a paper storage section such as a paper cassette or paper deck one by one and supplies them to an image forming processing section. . Conventionally, in so-called high-speed copying machines that can make a relatively large number of copies per unit time, in order to increase the copying speed, the previous paper is fed and the processing of the previous paper is scheduled after a certain period of time. Control was performed such that it was assumed that the paper was progressing as expected and the feeding of the next sheet was started.

However, with this control, if the paper being fed slips on the conveyance path or the leading edge of the paper that is being fed is slightly uneven within the storage unit, it may cause a paper jam or the paper may not be processed for image formation. This method has a disadvantage in that it causes a shift in the timing of secondary paper feeding (so-called registration timing) for supplying the paper to the section.

As a conventional technique for solving such drawbacks, for example, as described in Japanese Patent Application Laid-Open No. 59-212340, the ideal paper transport time and the actual paper transport time are compared and the difference is calculated. There was one that fed back the information to the secondary paper feeding timing of the registration section.

<Problems to be Solved by the Invention> Incidentally, recent high-speed copying machines have not only become faster but also have larger capacities so as to be able to make continuous copies of a large number of sheets.

For this reason, the conveyance path from the paper storage section to the registration section for performing secondary paper feeding tends to become longer. And for those with a long conveyance path from the paper storage section to the registration section,
When sheets are continuously fed at regular time intervals as described above, a plurality of sheets of paper are present on the conveyance path.

In such a situation, the above-mentioned Japanese Patent Application Laid-Open No. 59-2123
The control described in Japanese Patent No. 40 is not very useful, and has the disadvantage that it tends to cause paper jams. This is because the leading edge of the next paper that is already being conveyed is temporarily stopped at the registration section when the slip of the previous paper is detected, and the paper is temporarily stopped at the registration section to control the secondary paper feeding timing. This is because the paper may collide with the trailing edge of the stopped paper.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a paper feed control device suitable for a large-capacity, high-speed paper feed device in which a plurality of sheets of paper are simultaneously present on a conveyance path.

Means for Solving the Problems> The present invention is a paper feed control device for feeding sheets of paper stored in a paper storage section one by one to a predetermined processing section, a paper feeding means for feeding paper; a paper detection means for detecting a leading edge and a trailing edge of the paper fed by the paper feeding means; and measurement in response to the paper detection means detecting the trailing edge of the paper. a measuring means that starts the operation and derives an output when a time corresponding to a predetermined minimum required paper interval has elapsed; The paper feeding means is activated to start feeding the next paper, and in response to the paper detection means detecting the leading edge of the next paper, the paper feeding means is temporarily stopped, and the paper feeding means is temporarily stopped in response to the output of the measurement means. The paper feed control device includes a paper feed control means for operating the paper feed means.

Function> The paper fed out from the paper storage section is stopped when the leading edge of the paper is detected by the paper detection means, and paper feeding starts from that position, so that the paper to be fed always starts from the fixed position. become.

In addition, the measuring means allows the next paper to be fed out after a time corresponding to the minimum required paper spacing, which reduces the paper spacing to below the desired spacing and prevents paper collisions and paper jams on the conveyance path. It never occurs.

<Embodiment> Hereinafter, a copying machine will be described in detail as an embodiment of the present invention with reference to the drawings.

FIG. 2 is an illustrative diagram showing a schematic configuration diagram of a paper feeding mechanism of a copying machine according to an embodiment of the present invention.

This copying machine is equipped with three paper storage sections 12, 13 and 14. And each paper storage section 12゜13.14
Corresponding to the forward feed rollers 15, 16, and 17, respectively,
Paper feed rollers 18, 19. 20° retard rollers 21, 22
．． 23 and paper detection switches 24, 25, and 26 are provided. The advance rollers 15, 16, and 17 are used to feed out the sheets stored in the corresponding sheet storage sections 12, 13, and 14 in order from the top. Further, the paper feed rollers 18, 19, and 20 are for sending out the fed paper. On the other hand, paper feed rollers 18, 19.
20 and tart roller 21.2
2.23 rotates in the opposite direction to the corresponding paper feed roller with a weaker torque than the paper feed roller, and the paper feed rollers 18, 19 .
This is to prevent double feeding of paper due to 20. Normally, each set of advance roller, paper feed roller, and retard roller is activated or stopped at the same time by a paper feed clutch (not shown), respectively.
These constitute the primary paper feeding means.

The leading and trailing edges of the sheets fed by each primary sheet feeding means are detected by the sheet feeding switches 24, 25 or 26, respectively.

In addition, the primary fed paper is fed by feed rollers 27 and 28.
．． 29 and applied to the registration rollers 31 via the loop rollers 30.

A registration switch 32 is provided on the downstream side of the loop roller 30 and on the upstream side of the registration roller 31, and the sheet applied to the registration roller 31 can be detected by this registration switch 32. The registration roller 31 secondarily feeds the paper to the photosensitive drum 10 at a predetermined timing. The loop roller 30 provided on the upstream side of the registration rollers 31 advances the paper even when the leading edge of the conveyed paper hits the registration rollers 31 and stops, and gives the paper a certain level before the registration rollers 31. This is to create a deflection (loop).

When the paper is deflected in this way, the leading edge of the paper can be brought into sufficient contact with the registration rollers 31, and skewed feeding of the paper can be corrected.

The paper that is secondarily fed by the registration rollers 31 is brought into close contact with the surface of the photosensitive drum 10 , and the toner image developed by the developing device 11 is transferred by the transfer charger 33 .

FIG. 3 is a block diagram showing the configuration of an electric circuit for operating the mechanism of FIG. 2. As shown in FIG. 3, the electric circuit includes a CPU 34 as a control center;
The configuration includes a ROM 35 storing operating programs, a RAM 36 for storing data, etc., and an input/output interface 37. The RAM 36 is provided with a first timer area 361 and a second timer area 362 necessary for control, which will be described later.

The outputs of the paper feed switches 24, 25, 26 and the registration switch 32 described above are all provided to the CPU 34 via the input/output interface 37. Further, a control signal outputted from the CPU 34 is applied to the paper feed clutches 39 and 40° 41, the loop clutch 42, and the registration clutch 43.

Here, the paper feed clutches 39, 40, and 41 are, respectively,
Each primary paper feeding mechanism (advance roller 15, paper feed roller 18, retard roller 21 set, advance roller 16, paper feed roller 19)
．． Set of retard rollers 22 and advance rollers 17. Paper feed roller 20. This is for switching the operation/stop of the set of retard rollers 23). The loop clutch 42 is for switching between operation and stop of the loop roller 30. The registration clutch 43 is for switching the operation/stop of the registration roller 31.

FIGS. 1A, 1B, and 1C are flowcharts showing the control operation of the paper feeding mechanism of this copying machine.

FIG. 4 is a timing chart showing the operation of this copying machine.
The relationship between the paper feed switch 24, 25 or 26 and the timer is shown. Note that in FIG. 4, portions corresponding to the control of step numbers in FIGS. 1A and 1B are numbered with a recessed O.

Next, while referring to FIGS. 2 to 4, FIG. 1A,
The control operation of this embodiment will be explained according to the flow shown in FIGS. 1B and 1C.

When the main switch of the copying machine is turned on (step Sl
), the CPU 34 turns on the power and turns on the three paper feed clutches 39, 40, and 41 (step S2).
. Then, based on the paper feed switch 24°25.26 being turned on (step S3), the corresponding paper feed clutch 39, 40, 41 is turned off (step S4).

As a result, the leading edge of the first sheet of paper stored in the three paper storage sections 12, 13, and 14 is fed out to the positions of the paper feed switches 24, 25, and 26, respectively.

Next, in this state, it waits for a copy start signal to be given (step S5), and when the copy start signal is given by pressing the print button on the operation section, etc.
In order to feed the selected paper, the CPU 34
The corresponding paper feed clutch 39, 40 or 41 is turned on (step S6).

Also, a paper feed clutch off timer is set as a second timer using the second timer area 362 (step S7
).

This paper feed clutch off timer is set at step 8 in FIG. 1B.
Time subtraction operations are performed as shown in 71 to 873. Then, the CPU 34 turns off the paper feed clutch 39, 40 or 41 that has been turned on after the predetermined time t2 has elapsed (step 5).
74).

When paper feeding starts and the paper is conveyed by the feed rollers 27, 28 or 29, the trailing edge of the paper eventually passes the paper feed switch 24.25 or 26, and at that time, the paper feed switch 24.25 or 26 is turned off (step S
8). Therefore, the CPU 34 switches the paper feed switch 24.25.
Or, based on the detection of the off-edge in step S9), turn on the paper feed clutch 39, 40 or 41 again.
At the same time, a predetermined time t1 is set in the timer area 361 of the RAM 36, and a paper interval timer is activated as the first timer (step 510).

Here, the time t1 is set to a time corresponding to the minimum necessary paper interval, that is, the interval between the trailing edge of the previous paper and the leading edge of the next paper.

The paper interval timer is set at steps 8101 to 51 in FIG. 1C.
Perform time subtraction operation as in 04.

When the set time t1 has been counted (step 5104), the CPU 34 determines the output (step 813), turns on the paper feed clutch 39, 40 or 41 (step S6), and turns on the paper feed clutch off timer. It is activated (step S7) and the same control as described above is repeated.

In step 313, if the paper interval timer has not timed up, the on-edge detection of the paper feed switch 24, 25 or 26 causes the paper feed clutch 39, 40 or 4 to
Turn off 1.

Further, when copying is completed in step S12, the process returns to step S5.

Note that to determine whether copying is complete, for example, if the number of copies is set, the counter will subtract the number of copies each time one copy is processed, and until the remaining number of copies reaches 0, it will be determined that the copying has ended. An arrangement could be employed in which the signal is provided to the CPU 34, or other arrangements could be employed.

Since this embodiment is controlled as described above, the leading edge of the paper is fed out to the paper feed switch position before the paper feeding starts, and the leading edge of the paper is always fed out when paper feeding starts. Start from a fixed position. Therefore, even if there is some variation in the leading edge of the paper in the paper storage section 12, 13 or 14, regardless of this, at the start of paper feeding,
The leading edge of the paper always starts from a fixed position.

Although the above description has been made using an electrophotographic copying machine as an example, the present invention can be similarly applied to other paper feed control devices such as printing machines and electrophotographic facsimile machines.

<Effects of the Invention> Since the present invention is configured as described above, even if there is variation in the leading edge of the paper in the paper storage section, the paper is not detected until the leading edge is detected by the paper detecting means before paper feeding starts. Since the paper is fed out in advance, the paper will always start feeding from a fixed position.

In addition, since paper feeding is performed with a minimum required interval between sheets, even if sheets collide with each other on the conveyance path or slip during paper feeding, this will reduce the interval between sheets and cause paper jams. It is possible to provide a paper feed control device with less.

[Brief explanation of the drawing]

FIG. 1A, FIG. 1B, and FIG. 1C are flowcharts showing the control operation of one embodiment of the present invention. FIG. 2 is a diagram showing a schematic configuration of the main part of the present invention. FIG. 3 is a block diagram showing the configuration of an electric circuit according to an embodiment of the present invention. FIG. 4 is a timing chart for explaining the control operation of the present invention. In the figure, 12, 13, 14...paper storage section, 18
．． 19.20...Paper feed roller, 24,25.26...
・Paper feed switch, 34...CPU, 36...RAM
. 39.40.41...Paper feed clutch, 361...Timer area.

Claims (1)

[Scope of Claims] 1. A paper feed control device for feeding sheets of paper stored in a paper storage section one by one to a predetermined processing section, the device for feeding out the sheets of paper stored in the paper storage section. a sheet feeding means; a sheet detecting means for detecting a leading edge and a trailing edge of the sheet fed by the sheet feeding means; a measuring operation being started in response to the sheet detecting means detecting the trailing edge of the sheet; a measuring means for deriving an output when a time corresponding to a predetermined minimum required paper interval has elapsed; and a measuring means for activating the paper feeding means in response to the paper detecting means detecting the trailing edge of the paper to feed the next paper. Feeding is started, and in response to the paper detecting means detecting the leading edge of the next paper, the paper feeding means is temporarily stopped, and the paper feeding means is operated in response to the output of the measuring means. A paper feed control device comprising: a paper feed control means;