JPS5922833A - Paper feed controller - Google Patents

Abstract

PURPOSE:To make copying speed in a large number of sheets of paper increasable while preventing these sheets of paper from overlapping each other, by detecting an interval of each paper with a paper sensor installed in a paper feeding channel, and controlling to compensate the feed rate according to the detected output. CONSTITUTION:The detected output of a paper sensor 8 consisting of a luminous diode LED and a phototransistor PT is taken in a control device 26 and an interval between a preceeding sheet of paper and a succeeding sheet of paper obtainable from the detected output is compared with a reference value of that interval. And, when the paper interval is proper, a clutch 24 is connected and a sprocket 20 being large in diameter (low speed) is coupled with a sprocket 13 driving a paper feed roller 3, a separation roller 4a and a conveying roller 5a via a chain 18. On the other hand, when the paper interval is so judged as large enough, a clutch 25 is connected and a sprocket 21 being small in diameter (high speed) is as well coupled with the sprocket 13, transmitting the turning force of a motor 17 thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a paper feeding device for a copying machine, a printing machine, etc., and particularly to a paper conveyance control device for this paper feeding device.

2. Description of the Related Art Generally, in a paper feeding device of a copying machine, even-spaced paper feeding control is performed when the paper stored in a container is sent one by one into a conveyance path by a paper feeding roller.

However, due to variations in the way the sheets are placed in the container, or differences in the coefficient of friction between the sheets and the paper feed roller, there are cases where the sheets are not necessarily conveyed at regular intervals. That is, there are cases where the paper interval is too long.

However, it is not possible to control the paper feeding interval so that the interval is too short in anticipation of such a long paper interval.

This is because, in this case, the trailing edge of the preceding paper and the leading edge of the succeeding paper may overlap.

The present invention has been developed in view of the above circumstances, and is a paper conveyance control device fj that detects a paper interval 2 using a paper sensor provided in the conveyance path and controls the correction of this interval.
j! , the purpose is to provide.

An embodiment of the present invention will be described below based on the drawings.

FIG. 1 is a simplified side view showing a paper feeding device of a copying machine.

In the figure, reference numeral 1 denotes a paper feed tray, and sheets P are stacked on a bottom plate 2 that can be moved up and down. The paper P is sent out by a paper feed roller 3, but is first separated one by one by a pair of separation rollers 4. The separation roller pair 4 is a roller 4 rotating in the forward direction.
This is a known type consisting of a roller 4a rotating in the opposite direction and a roller 4b rotating in the opposite direction. Roughly, the paper P is conveyed through a conveyance path 7 to a resin roller 6 by a pair of conveyance rollers 5 . Then, it is roughly sent to processing stations such as a transfer position and a fixing position. The conveyance roller pair 5 is composed of a drive roller 5a and a driven roller 5b, and the registration roller 6 is similarly composed of a drive roller 6a and a driven roller 6b. 8 is this transport route 7
This is a reflective optical paper sensor installed inside.

FIG. 2 is an explanatory diagram showing a drive transmission system for each of these rollers.

In the figure, there is a paper feed roller 3 and a separation loaf pair 4.

- roller 4a, drive roller 5a of transport roller pair 5, and drive roller 6a with registration roller are provided with sprockets 9, 10, 11.12, respectively,
l-9, 10, 11 form a loop with a tin rocket 13, which will be described later, and the sprocket 12 has x, 7' o
It is Q so as to form a loop with Kerato 14. The tin rocket 14 is attached to the motor 1 along with sprockets 15 and 16.
It is attached to 7.

], 8, and 19 are chains for constructing the loop described above. Further, the sprocket 15 is connected to a tin rocket 20, and the sprocket 16 is connected to a tin rocket 21 through chains 22 and 23, respectively. The sprocket (sprocket) 20.21 is coaxial with the sprocket 13, and the rotational speed according to the diameter of the sprocket 20 and the rotational speed according to the diameter of the sprocket 21 are applied to the sprocket 13 by electric and magnetic clutches 24.25. It is meant to be transmitted. In this case, the diameter of the sprocket 20 is larger than the diameter of the sprocket 21. Same, motor 1
The tin rockets 15° and 16 attached to the shaft of 7 have the same diameter.

Since the drive transmission system is like this, when the clutch 25 is engaged, the paper feed roller 3. The rotation of roller 4 a + drive roller 5 a is fast, and when the clutch 24 is engaged, the rotation of each stiff roller becomes slow.

Further, the drive rollers 6a of the registration roller pair 6 are rotated independently.

FIG. 3 shows an embodiment of a control circuit showing the relationship between paper detection by the paper sensor 8 and clutch control output.

In the figure, the paper sensor 8 consists of a light emitting diode LED and a phototransistor I)T. Also, in the figure R, ~
R6 is a resistor, zD is a Zener diode, Q1 to Q5 are transistors, and Q2, Q3, Q4, and Qs each constitute an amplifier circuit.

The clutches 24' and 25 are driven by this amplifier circuit output. And 26 is a control device 20 composed of a CPU and the like. In this control rack @26, there is a preceding paper P in the transport path 7! There is a part that stores a reference value for the distance between the paper P2 and the following paper P2, a comparison part that takes in the detection output from the actual paper sensor 8 and compares it with the reference value, and an output part that outputs the comparison result.

FIGS. 4(a) and 4(b) are timing charts.

In the figure, (1) is the paper sensor output, and PI *
p2 is the detection waveform of the preceding paper and the following paper, and T 1 *
T2 is their interval (T2>TI). (2)
is the drive output of the clutch 24, and (3) is the drive output of the clutch 25.

As is clear from this timing chart, when the paper spacing is appropriate (reference value) as shown in (,), the clutch 24 that transmits drive to the tin rocket 20 with a slow rotation speed (large diameter) is driven. An output signal is output from the output terminal 01 of the control device 26.

On the other hand, if the gap between the sheets is too wide as shown in FIG.
An output signal is output from the output terminal 02 of.

As described above, the present invention is designed to detect the intervals between multiple sheets of paper being conveyed in the paper conveyance path and correct the conveyance speed of the sheets, thereby preventing malfunctions such as paper unloading. This has the effect of increasing copying speed for a large number of sheets without causing problems.

[Brief explanation of drawings]

FIG. 1 is a simplified side view showing a paper feeder section of a copying machine, FIG. 2 is an explanatory diagram showing a drive transmission system according to an embodiment of the present invention, and FIG. 3 is an embodiment of paper detection and drive control. The circuit diagram shown in FIGS. 4(a) and 4(b) are timing charts of each part during normal conveyance and abnormal conveyance, respectively. DESCRIPTION OF SYMBOLS 1... Loading means, 3... Sending means, 4, 5... Conveying means, 8... Paper sensor, 24.25... Clutch, 26... Control device. 2nd figure

Claims (1)

[Claims] In a paper feeding device comprising a paper loading means, a feeding means for feeding the paper one sheet at a time from the stacking means, a conveyance means for conveying the fed sheets to a processing station, and a paper sensor provided in the conveyance path. , a storage means for storing a standard interval between a preceding sheet and a following sheet of sheets conveyed at a constant interval, a comparing means for comparing this standard interval and an interval of a sensor output by the paper sensor, and a sensor whose output is equal to or greater than the standard interval. A paper conveyance control device comprising: an output means that outputs an output at output intervals; and the output from the output means controls a clutch that increases the rotational speed of the sending means and the conveying means.