JPS5854058B2 - Kaminashi Kenchi Souchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a paper out detection device that detects when paper runs out in a machine such as a copying machine that uses paper.

Conventionally, some copying machines detect that there is no paper in the paper feeder and issue an alarm and stop the copying operation. The last piece of paper remains inside and is wasted.

Therefore, there is a system in which, after detecting that there is no paper in the paper feeder, a timer issues an alarm after the time elapses from paper feeding to paper ejection to stop the copying operation.

However, since the scheduled time from paper feeding to paper ejection is set in the timer, the time when the last sheet of paper is ejected and the time when the timer's output signal is output are inevitably different, and the timer's output signal is If the timer output signal is output too early, the copying operation will stop before completing the copying operation for the last sheet, and if the timer output signal is output too late, the copying machine will run idly, and the time from paper feed to paper ejection will be too long. Since it changes depending on the speed, it becomes more difficult to issue the timer's output signal with accurate timing.

SUMMARY OF THE INVENTION An object of the present invention is to provide a paper out detection device that can eliminate the above-mentioned drawbacks and accurately detect when paper is out.

An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, in a copying machine, when a print button is pressed, a sheet of transfer paper 2 is automatically sent out from a paper feeder 1.

Although this paper feeding device 1 uses a cassette containing a large number of transfer sheets of predetermined sizes, it may also cut roll paper into a predetermined size and send it out.

The transfer paper 2 sent out from the paper feeder 1 is conveyed along a predetermined conveyance path 3. On the way, the toner on the photoreceptor 4 is transferred and fixed by the fixing device 5, and the copy is placed on the paper output tray 6. It is discharged as.

A plurality of detection elements SW1 to SW3 are installed at a plurality of locations on the transport path 3.

For example, the detection elements SW1 to SW3 are arranged at a position in the paper feeder 1 to detect the transfer paper 2, in the middle of the conveyance path 3, and at a position to detect paper discharge onto the paper discharge table 6.

The detection elements SW1 to SW3 may be mechanical switches or non-contact detection elements.

As shown in FIG. 2, when the power is turned on in the copying machine and the heater of the fixing device 5 is energized by the heater control circuit 7 and starts up, the flip-flop 8 for the heater start-up memory is set by the signal from the heater control circuit 7. be done.

Next, when the print button is pressed, the print button activates a switch and generates a copy start signal.

This copy start signal passes through AND gate 9, and the output of flip-flop 8 passes through AND gate 10, setting flip-flop 11 for copy cycle memory.

The output signal of the flip-flop 11 puts each load, that is, each device of the copying machine, into a standby state, and furthermore, a paper feed signal is generated, the paper feed device 1 sends out the transfer paper 2, and the paper feed memory flip-flop 12 is activated. Set.

Next, the transfer paper from the paper feeder 1 is conveyed to the detection element S.
When detected by W2, the output signal of this detection element SW2 sets the paper transport memory flip-flop 13 as a paper transporting signal, and at the same time resets the paper feed memory flip-flop 12.

Next, when the transfer paper 2 is detected by the detection element SW3, the flip-flop 14 for paper discharge memory is set by the rising detection pulse of the output signal of this detection element SW3, and at the same time, the flip-flop 13 for paper transport memory is reset. At the same time, the discharge memory flip-flop 14 is reset by the falling detection pulse of the output signal of the detection element SW3, and at the same time, the interrogation pulse generation circuit 15 is driven to generate an interrogation pulse.

The rising edge detection pulse is generated when the transfer paper begins to be ejected onto the paper ejection tray 6, and the falling detection pulse is generated when the transfer paper is finished being ejected onto the paper ejection tray 6.

Therefore, an interrogation pulse is generated every time a sheet is ejected, and a flip-flop 12 for paper feed memory, a flip-flop 13 for paper transport memory, and a flip-flop 14 for paper ejection memory are used to detect transfer paper when it is fed, conveyed, and ejected. Remember.

The interrogation pulse is passed through the AND gate 16 by the inverted output signals of the flip-flops 12-14 and is applied to the AND gate 18 together with the output signal of the paper out detector 17.

The paper out detector 17 is configured using a detection element SW1,
An output signal is generated when there is no paper in the paper feeder 1.

When the output signal of the paper out detector 17 is generated, the interrogation pulse passes through the AND gate 18 to turn on the paper out indication, and passes through the OR gate 19 via the diode 20 to reset the copy cycle memory flip-flop 11. The copying operation is stopped, and the gate 9 is closed via the diode 21 to inhibit the copy start signal so that the copying operation is not started.

As shown in the time chart of FIG. 4, the interrogation pulse is generated every time a sheet is discharged and is applied to the AND gate 16, to which the inverted output signals of each of the flip-flops 12 to 14 are also applied.

Therefore, even if a signal is output from the out-of-paper detector 17 when paper is traveling inside the copying machine, an output signal from the AND gate 16 is not output, so no output signal is output from the AND gate 18.

When a signal is output from the out-of-paper detector 17, the AND gate 18 is activated only after the paper inside the copying machine is ejected to the outside paper output tray 6.
An output signal is output as a paper out detection signal.

These out-of-paper detection operations are performed in conjunction with various jam detection circuits.

The timer T1 is set simultaneously with the paper feed memory flip-flop 12 by the paper feed signal.

This timer T and the output signal of the flip-flop 12 are applied to the ant gate 22, and if the flip-flop 12 is not reset due to some abnormality, an output signal is outputted from the AND gate 22 as a paper feed section jam detection signal. The copy cycle memory flip-flop 11 is reset through the gate 19, and the gate 9 is closed to inhibit the copy start signal.

Similarly, the timer T2 is set by the paper conveyance signal at the same time as the paper conveyance memory flip-flop 13, and the output signals of the timer T2 and the flip-flop 13 are applied to the AND gate 23.

If there is an abnormality and the flip-flop 13 is not reset, an output signal is output from the AND gate 23 as a transport section jam detection signal and sent to the OR gate 19.

Also, the timer T3 is a flip-flop 14 for paper discharge memory.
At the same time, the output signal of the timer T3 and the flip-flop 14 is set by the rising edge detection pulse and is applied to the ant gate 24.

If there is an abnormality and the flip-flop 14 is not reset, an output signal is outputted from the ant game 124 as a paper discharge section jam detection signal and sent to the OR gate 19.

In this case, the timers T1 to T3 are the time from when the paper feed signal is output until the paper reaches the detection element SW2, the time the paper is conveyed between the detection elements SW2 and SW3, and the time the paper is conveyed for that length. A fixed time is set, each longer than the time.

When the original has been copied by the number of copies set by the counter 32, the gate 33 is opened by the output of the counter 32, and the copy cycle memory flip-flop 11 is reset by the copy cycle out signal.

As shown in FIG. 3, the jam in each part is displayed by turning on transistors 25-27 in response to the output signals of antenna gates 22-24 and lighting lamps L1-L3.

Further, the output signal of the AND gate 18 is applied to the AND gate 28 together with the output of the free-running multi-by-break M, and the output signal of the AND gate 28 is applied to the transistors 25 to 27 via the diodes 29 to 31, so that the lamps L□ to
By flashing L3, a paper out display is performed and an alarm is issued.

If a jam and out of paper occur at the same time, the jam is displayed with priority.

As described above, according to the out-of-paper detection device according to the present invention, the out-of-paper state in the paper feeder is detected by the out-of-paper detector, and an interrogation pulse is generated every time a paper is ejected, and this interrogation pulse is output from the out-of-paper detector. A signal is generated to detect that the storage device does not remember when the paper passed and output it, so it is possible to accurately detect when the machine is out of paper.Moreover, since a jam detection device is used, the configuration becomes easier.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an example of a copying machine to which the present invention is applied, FIG. 2 is a block diagram showing an embodiment of the present invention, and FIG. 3 is a circuit diagram showing a part of the embodiment. FIG. 4 is a time chart of the above embodiment. 15...Question pulse generation circuit, 16...
・And gate, 17...Paper out detector, 18
... Ant gate.

Claims (1)

[Claims] 1. A paper feeding device that feeds paper in response to a paper feeding signal, a conveyance path through which the paper fed from the paper feeding device is conveyed, a plurality of detection elements that detect paper at multiple locations on this conveyance path, and The time of paper passage is stored in a storage device for each section using the output signals of the plurality of detection elements and the paper feed signal, and the paper jam is detected for each section using the output of this storage device, the output signal of the detection element, and the paper feed signal. A machine having a jam detection device for detecting a paper out state in the paper feeding device, and an interrogation pulse generating means for generating an interrogation pulse each time paper is discharged from the conveyance path. and a means for detecting that the storage device does not remember the time of paper passage by generating an interrogation pulse from the interrogation pulse generation means and an output signal of the paper out detector.