JPS63127968A - Roll paper detector in electrophotographic machine - Google Patents

Abstract

PURPOSE:To detect run out of paper accurately in short time through a simple structure, by providing a rotation detector for outputting a rotation detection signal corresponding to the moving amount of a roll paper and a timer being started by the variation of the detection signal. CONSTITUTION:A roll paper 6 or 7 is fed by pickup rollers 12, 13 and cut into a sheet of specific size by means of a cutter 903 then fed to a photosensitive drum 2. During this process, the moving amount of the roll paper 6, 7 is detected by a rotation detector 957 coupled to a driven side roller of a feed roller 902. Every time when a pulse signal is fed from the rotation detector 957, a control circuit 951 initiates a resetable timer 970, and if the timer is not initiated within a predetermined time (0.5 sec., for example), count up is carried out, thereby run out of paper can be detected whether or not a roll paper is adhered to a core when paper existence and paper run out signals being fed from optical sensors 955, 956 are combined. Consequently, run out of paper can be detected accurately in short time through simple structure.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a roll paper presence/absence detection device for an electrophotographic device, and particularly for a roll paper presence/absence detection device for an electrophotographic device that can reliably detect the absence of roll paper with a simple device. The present invention relates to a paper presence/absence detection device.

[Conventional technology]

Generally, examples of electrophotographic devices include copying machines, electrophotographic printers, telephone facsimile machines, and the like. Such an electrophotographic apparatus forms a latent image on a photosensitive drum having a photosensitive member, converts the latent image into a visible image using a developing device, and transfers this visible image to copy paper, after which the copy paper is heated or It is known as a device that fixes a visible image on a paper surface by applying pressure, and the method of forming the latent image differs depending on the various electrophotographic devices.

By the way, the above-mentioned electrophotographic apparatus that uses roll paper to supply copy paper has the roll paper built into the electrophotographic apparatus, and the roll paper is cut to a preset length when copying, etc. is cut with a cutter and then used.

In addition, the electrophotographic apparatus is equipped with a detection means that can detect the presence or absence of roll paper loaded in the apparatus, and when the detection means detects that the roll paper is running out, the cutter and paper feed Configured to stop operation of the device. For roll paper used in such electrophotographic devices.

One is made by gluing the end of a band-shaped copying paper to a core and winding the paper around the core, and the other is made by winding the paper around a core without bonding the end of a band-shaped copying paper to the core. There are two types, and these are used as appropriate.

By the way, conventional roll paper presence/absence detection means includes a reflective light detection element that is placed opposite to the surface of the roll paper wound on the core, and detects changes in reflected light between the roll paper and the black-painted core. It used a detection element to detect the absence of paper.

However, the above-mentioned conventional roll paper presence/absence detection means has the disadvantage that malfunction may occur due to changes in reflected light depending on the number of rolls of roll paper or due to adhesion of paper scraps to the photodetector element.

As a solution to the above-mentioned inconvenience,
A roll paper presence/absence detection device described in No. 73 has been proposed. With such a device, all of the above-mentioned disadvantages will be eliminated.

[Problem that the invention seeks to solve]

However, the roll paper presence/absence detection device has a pulse signal transmitter that generates a pulse signal in synchronization with the rotation of a driven roller that rotates as the roll paper moves, and based on the pulse signal from this transmitter, , generates an inverted pulse of a predetermined width from this pulse signal, generates a delayed pulse delayed by a certain amount of time from the pulse signal from the transmitting device, and calculates the paper by performing the logical product of these inverted pulses and the delayed pulse. Since it is used to detect

The pulse signal must be of a certain format and, in addition, a long period of time (at least 2
There was a problem in that the pulse time required).

The present invention has been made to solve the above-mentioned problems, and its purpose is to provide a roll paper presence/absence detection device for an electrophotographic apparatus that can accurately detect paper out in a short time with a simple configuration. be.

[Means for solving problems]

A roll paper presence/absence detecting device in an electrophotographic apparatus according to the present invention that achieves the above object is provided with a photosensitive drum having a photosensitive member on which a latent image is formed, and a device provided around the photosensitive drum to convert the latent image into a visible image. a developing device for transferring the visible image to the copy paper while the copy paper is in contact with the photosensitive drum; A fixing device that fixes the image, and a transport mechanism that takes out the roll paper from a storage box that stores the roll paper, cuts it into a predetermined length with a cutter to make copy paper, and transports it to the photosensitive drum, the fixing device, and outside the apparatus. a rotation detector provided in the transport mechanism and outputting a rotation detection signal according to the amount of movement of the roll paper; and a rotation detector provided with a rotation detection signal according to the amount of movement of the roll paper; It is activated by a change in the signal, and has a timer that always counts from the beginning when activated and counts up after a certain period of time if it is not activated. This feature is characterized in that it is configured so that it is determined that there is no paper left when it is detected that the paper is out of paper.

[Effect]

If there is paper, the roll paper is transported by the feeding device, and the detection signal changes as the paper moves through the rotation detector, so the timer does not count up. Therefore, it is detected that one sheet is present.

Next, if one paper is missing, the rotation detector will not rotate if the end of the roll paper is glued to the core, while if the end of the roll paper is not glued to the core, the end of the roll paper will not rotate. Since it passes the rotation detector and does not rotate in the same way, there is no change in the detection signal from the one rotation detector, so the timer is not started and the timer counts up. Therefore, in this case, it is possible to detect that there is no paper.

〔Example〕

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

FIG. 1 is a block diagram showing an embodiment of the present invention.

The electrophotographic apparatus shown in FIG. 1 is constructed as follows. That is, a photosensitive drum 2 having a photosensitive member 1 on which a latent image is formed, a developing device 3 provided around the photosensitive drum 2 to turn the latent image into a visible image, and a developing device 3 provided around the photosensitive drum 2, which has a certain amount of space around the photosensitive drum 2. a transfer device 4 which is provided at an interval of , and transfers a visible image onto the copy paper considering the charge from the back side of the copy paper when the copy paper is in contact with the photosensitive drum 2;
A fixing device 5 heats or presses the copy paper to which the visible image has been transferred to fix the visible image on the paper surface, and the roll paper 6 or 7 is taken out from the storage box 8 that stores the roll paper 6 or 7 and placed in a predetermined position. The photosensitive drum 2 is cut into length to make a copy paper.
, a feeding device 9 that feeds the copy paper to the fixing device 5 and discharges the copy paper out of the apparatus through a normal conveyance path when it is determined that the copy paper is longer than a length that does not cause a paper jam when the paper is detected to be out of paper. It is composed of:

The feeding device 9 includes a transport mechanism 900 that takes out the roll paper 6 or 7 in the storage box 8 and cuts it into a predetermined length to make copy paper, and then transports the paper to the photosensitive drum 2 and the fixing device 5. and a control system 9 that controls the drive of the transport mechanism 900.
It consists of 50.

Next, the transport mechanism 900 will be explained.

The transport mechanism 900 is configured as follows.

Wheels 11 are provided at the bottom of the base 10 as shown in the figure, and a storage box 8 for storing a plurality of roll papers 6 and 7 is provided on the base 10.
is provided so that it can be inserted and removed in the direction of the arrow in the figure. The storage box 8 is provided with pick-up rollers 12 and 13 for taking out the roll papers 6 and 7, and these pick-up rollers 12 and 13 are engaged with a roller drive source and rotated when mounted in the illustrated state. It looks like this.

The roll paper 6 or 7 taken out by the pickup roller 12 or 13 passes through a guide 901 and is guided to a feed roller 902, one of which is a driving roller and the other is a rotatable driven roller. There is. A cutter 903 that cuts the roll paper 6 or 7 based on a cutting command is provided directly above the feed roller 902 in the drawing. The paper leaving the cutter 903 passes through a guide 904 and is guided to a conveyance roller 905. A leading paper folding device 906 is provided adjacent to the conveyance roller 905.

The paper that has passed through the paper folding device 906 is sent through a guide 907 between the photosensitive drum 2 and a transfer roller 908. The driven roller is pressed against the driving roller, and its rotation is frictionally transmitted through the roll paper being conveyed.The driven roller is placed at a common position where it can come into contact with the roll paper of the smallest usable width, in this example the roll paper. It is provided only at a position where it contacts the widthwise central portion of the The copy paper, on which the visible image has been transferred after passing between the photosensitive drum 2 and the transfer device 4, is conveyed on a belt 911 that is passed between rollers 909 and 910, and is inserted into the fixing device. go. The sheet of paper moved by the belt 911 is heated as it passes between the fixing roller and the backup roller of the fixing device 5 and the visible image is fixed thereon.
6 so that it is discharged outside the device.

The control system 950 is configured as follows.

In FIG. 1, reference numeral 951 is a control circuit, and the control circuit 951 may be constituted by a microcomputer system or the like, and the operation of the entire apparatus is controlled by this circuit 951.

The control circuit 951 includes an operation display panel 952 that inputs operation commands and displays various displays, and a retraction position sensor 953 that is used when retracting the unused roll paper 6 or 7.
or 954, a sensor 955 or 956 that detects the paper width size of the roll paper 6 or 7 and the absence of paper, and a rotation detection sensor that is attached to the rotating shaft of the driven roller of the feed roller 902 and rotates as the paper moves. A timing sensor 958 that detects the leading edge of a piece of paper and takes timing, and a sensor 959 that detects whether or not the paper has been ejected from the device are connected to the container 957, and various detection signals are inputted thereto. It looks like this.

Further, the control circuit 951 includes a cutter 903.

The roller drive source control device 960 and the operation display panel 952 are connected to each other, and supply a cutting command to the cutter 903 and a drive command to the roller drive source control device 960, respectively.

FIG. 2 is a block diagram showing the configuration of control system 950.

The control system 950 is configured as follows. That is,
The control circuit 951 includes a central processing unit (CPU) 951
0, a timer 9511 that applies an interlude to the CPU 9510 at regular intervals, and a read-only memory 9.
512, random access memory 9513, digital input port 9514, and digital output port 9515
, digital input/output capo)-9516, and pass line 9
517.

The digital input port 9514 has a sensor 953.
956, 958, 959, a rotation detector 957, and a resettable timer 970. In addition, digital output boat 951
5, a reset signal is output to the resettable timer 970, a cutting command is output to the cutter 903, and a drive command is output to the roller drive source control device 960. Digital input/output boat 951
6 is connected to an operation display panel 952.

Incidentally, the sensors 953 to 956 and 959 may be constituted by optical sensors that shine light onto paper and detect reflected light, and a light detection signal from the light receiving section may be used. The one-rotation detector 957 converts the rotation state into a pulse signal and extracts it. Its rotation axis is connected to the rotation axis of the driven roller of the feed roller 902, and when the roll paper moves, the pulse signal is output. Occur. Further, the resettable timer 970 is set to, for example, 0.5 [seconds], and when the timer 970 is activated by a command from the digital output board 9515, it starts counting from the beginning, and starts counting for a set fixed period of time (for example, 0.5 seconds). If it is not activated within 5 seconds, the count will increase. Note that, theoretically, the above-mentioned certain period of time is the rotation detector 9 rotating at a predetermined speed.
From rising (lower) to falling (upper) of the rotation detection signal from 57
It is sufficient that the time is slightly longer than the time it takes to complete the process.

The operation of the embodiment configured as described above is shown in FIGS. 3 and 4.
This will be explained with reference to the figures.

FIG. 3 is a flowchart shown to explain the operation of the embodiment of the present invention, and FIG. 4 is a flowchart shown to explain the operation of counting pulse signals from the rotation detector 957.

In FIG. 3, steps 8102 to 5106 are paper-out detection processing, steps 5L02 to 5103 are processing when the end of the roll paper is not adhered to the core, and steps 8104 to 5106 are processing when the end of the roll paper is not adhered to the core. This is the process when it is glued to.

First, in step 5101, the CPU 951 of the control circuit 951 determines in which size the roll paper is to be cut.
Judge by. Since this is selected by the operator in advance from the operation display panel 952, it can be easily determined based on the selection information.

If the roll paper size is the first size, step 51
If the size is the second size, the process moves to step 5103. In steps 5102, 103, the sensors 955, 9
56 is used to detect the presence or absence of paper. In other words, sensor 9
The CPU 95 determines that the roll paper is present when the light emitted from the 55,956 is applied to the roll paper and the reflected light is received, and that there is no roll paper when the reflected light is not received.
10 is sufficient. Also, the sensor 953°95
It goes without saying that paper-out detection is possible even if 4 is used. This means that the detection signal from the sensor 955 or 956 is taken into the CPU 9510 via the digital input port 9514, and the CPU 9510 makes a determination. When it is determined in steps 5102 and 103 that there is roll paper, respectively.

The process moves to step 5104. In step 5104, CP
U9510 stores ROLLMOTOREN in step 8204 shown in FIG. 4 in a predetermined area of RAM 9513.
CORDEREDGE (hereinafter referred to as RMEDGE)
Determine whether or not it is standing. This step 5104
Then, when RMEDGE is set, step 51
The process moves to step 05, but if RMEDGE is not set, it skips to step 8106. In step 5105, the CPU 9510 clears RMEDGE and activates the resettable timer 970, which is set to, for example, 0.5 seconds, via the digital output port 9515, and proceeds to step 8106. This timer 970
is outputting "OIT" before 0.5 [seconds] elapse after startup, and after 0.5 [seconds] elapse, "It I" is output to that output.
Since the configuration is such that II is set, this output is taken into the CPU 9510 via the digital input port 9514.

In this step 5106, the CPU 9510 determines whether or not the timer 970 has counted up and 1'' has been input to the digital input port 9514 from the output of the timer 970.
．． If 5 [seconds] have not elapsed, it is determined that there is paper, and 0.5 seconds have passed.
If [seconds] have elapsed, it is determined that there is no paper.

In this step 8106, also in step 5102.10
If it is determined in step 3 that there is no paper, the process moves to step 5107. In step 5107, the CPU 9510 first issues a paper out display command to the operation display panel 952 to display "paper out". Next, read the count value of the edge counter (described later).

It is determined whether this value is larger than, for example, a predetermined number r200J. This determination uses the value of the edge counter that counts the value according to the amount of movement of the roll paper to check whether the roll paper has moved in the direction of the cutter 903 by a predetermined number r200J) or more for a certain length. . This step 5
If the CPU 9510 determines in step 108 that the feeding length of the roll paper is longer than the predetermined length, the process proceeds to step 510.
However, if it is determined that the feeding length is shorter than the predetermined length, the process moves to step 5110. In step 8108, if it is determined that the paper is longer than a certain length,
Since the length of the paper in front of the cutter 903 is greater than the length of the paper that will not cause a paper jam, the CPU 9510 outputs a cutting command to the cutter 903 via the digital output port 9515, and also outputs a cutting command to the edge counter. Reset numbers. As a result, the process moves to step 5111, and a detection signal from the sensor 959 is inputted from the digital input port 9514 to determine whether the paper has come out of the apparatus.
It is determined by the PU 9510, and if it is missing, the process moves to step 5112, but if it is not missing, the process moves to the next flow. When it is determined in step 5l11 that the paper has come out of the apparatus, the CPU 9510 issues a roller stop command to the roller drive source control device 960 via the digital output port 9515. As a result, unnecessary paper is discharged from the apparatus.

On the other hand, if it is determined in step 3108 that the value of the edge counter is smaller than the predetermined number, this is because the paper is long enough to cause a paper jam.

In step 5110, it is determined whether or not there is a previous copy paper in the apparatus, and if there is no previous copy paper, the step 511
2, from CPU9510 to digital output port 9
If there is a previous copy sheet, a stop command is issued to the roller drive source control device 960 via the printer 515 in step 5.
Move to 111.

A series of operations are performed in this manner.

Next, the operation of the edge counter will be explained with reference to FIG.

The timer 9511 causes the CPU 9510 to e.g.
The process moves to interwoven processing every (m seconds).

Edge counter processing is performed within this interwoven processing. In addition, for this process, RAM95・
13, an area RMETE, an area RMELE, an edge counter count value area, and an area RMEDGE are provided. Also.

At initial time, area RMELE and area RMET
It is assumed that "011" is set in E.

■First, in step 5200, the CPU 9510 sends the detection signal from the rotation detector 957 to the digital input board 95.
14, and the detection signal is '1'' or II OI
Determine whether it is I or not. When the detection signal is u l rr, the process moves to step 5201 and the area R of the RAM 9513 is
Call 111 # for METE.

Next, the process moves to step 5202 and the state of area RMELE is checked.
' is set, the process moves to step 5203. In step 5203, the area RMELE is reset, and the process moves to step 5204, where the area RMEDGE is reset.
It stands up. This area RMEDGE is used during the operation shown in FIG.

Next, in step 5205, the edge counter area is incremented, and the series of processes ends.

■ Once again, if 4 [m seconds] of interlapping is applied,
CPU 9510 again takes in the detection signal of rotation detector 957 and makes the determination in step 5200. Normally, the edge counter processing speed in interlaced is faster than the signal from the rotation detector 957, so the detection signal remains at 1''.Therefore, based on the determination in step 5200, the process moves to step 5201.Step 5201 Now, area R
After setting METE to "1", the process moves to step 5202. In step 5202, the CPU 9510 checks the area RMELE and finds that it is 0'', so the process ends. This process continues as long as the detection signal from the rotation detector 957 is 151''.

(2) The interlaced signal is applied again, and edge counter processing is started. In step 5200, when it is determined that the detection signal of the rotation detector 957, which is taken into the CPU 9510, is "0", the process moves to step 8206. Step 820
In step 6, after setting II II II in area RMELE, the process moves to step 5207. In step 5207,
CPU9510 is.

Check area RMETE. In step 5207, since the area RMETE is rr 1 n, step 52
08, the area RMETE is cleared, and then the process moves to step 5204, and subsequent processing steps 5204 and 5
205, the signal of the rotation detector 957 becomes 7117
→# Finish the process immediately after changing to OIT.

■ When the interwoven process is entered again, the detection signal is “0”, so steps 5200 to 8206
Move to. It is set in the area RMETE in step 5206.
After setting 1 +j, the process moves to step 5207. In step 5207, the area RMETE is checked and this is “
0'', the edge counter processing is terminated. This process is performed when the detection signal from the one-rotation detector 957 is 0'.
It continues for a long time.

■ When interwoven processing is started again and edge counter processing is started, in step 5200, the rotation detector 95
When it is determined that the detection signal No. 7 has changed from 'O'' to rr 1 rt, the process returns to the edge counter processing No. 2 above.

Note that the count value of this edge counter is normally used to measure the size of the roll paper, and is cleared each time a cutter cutting command is output.

Further, in the above embodiment, the resettable timer 970 is configured with hardware, but it may of course be configured with a software timer.

Another embodiment of the present invention will be described with reference to FIGS. 5 and 6.

FIG. 5 is a configuration diagram showing an embodiment other than the present invention.

The other embodiment differs from the above embodiment in that the rotation detector 957 is not attached to the rotating shaft of the driven roller of the feed roller 902, but the rotation detector 957 is
A driven roller 920 is newly installed at the front stage of the driven roller 920, and the rotating shaft of a rotation detector 957 is attached to the rotating shaft of one of the driven rollers 920. The only difference is that the signal is generated, and there are no changes to other components. Therefore, the same components are given the same reference numerals and their explanations will be omitted.

The operation of this embodiment will be explained based on FIG.

Further, the flowchart shown in FIG. 4 is also used in the operation of this embodiment.

The difference between the flowchart in FIG. 6 and the flowchart in FIG. 3 is that steps 8101 to 5103 are omitted, and whether or not the roll paper is glued to the core, there is no paper in steps 8104 to 8106. The point is that it is possible to detect.

In other words, when the roll paper is adhered to the core, the operation is the same as that in FIG. 3. If the roll paper is not adhered to the core, if the final end of the roll paper passes the driven roller 920, the driven roller 920 will no longer rotate, and the rotation detector 957 will no longer generate a pulse signal. Then, since there is a pulse signal before that, the pulse signal is no longer inputted to what was mainly operating in steps 5104, 5105, 5106, and 5ill, so by executing the processing in steps 5104 and 5106, When a certain period of time has elapsed (step 510
6), it will be detected that there is no paper.

When the pulse signal is input in this way, the resettable timer 970 is activated, and when the next pulse signal is not input within the time set in the resettable timer 970, it is possible to detect that there is no paper. This is what I did.

Note that in other embodiments, the resettable timer 970 is
Of course, a timer is better than software.

〔Effect of the invention〕

As described above, according to the present invention, there is an effect that paper out can be detected accurately and in a short time with a simple configuration.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a roll paper presence detection device in an electrophotographic apparatus according to the present invention, FIG. 2 is a block diagram showing a control system of the embodiment, and FIG. 3 shows the operation of the embodiment. FIG. 4 is a flowchart shown to explain the operation of the edge counter; FIG. 5 is a flowchart shown to explain the operation of the edge counter.
The figure is a block diagram showing another embodiment of the present invention, and FIG. 6 is a flowchart shown to explain the embodiment. 2......Photosensitive drum, 3...
・・・・・・Developing device, 4・・・・・・・・・・・・
Transfer device, 5...Fixing device. 6.7... Roll paper. 8......Storage box, 9...Feeding device, 10...
...base. 900... Conveyance mechanism. 950...Control system.

Claims (1)

[Claims] (1) A photosensitive drum having a photosensitive member on which a latent image is formed;
a developing device that is provided around the photosensitive drum and converts the latent image into a visible image; and a transfer device that transfers the visible image onto the copy paper in consideration of electric charge when the copy paper is in contact with the photosensitive drum. a fixing device that fixes the visible image onto the copy paper onto which the visible image has been transferred; and a fixing device that fixes the visible image on the copy paper onto which the visible image has been transferred; , an electrophotographic apparatus comprising the photosensitive drum, a fixing device, and a feeding device having a conveying mechanism for conveying the paper to the outside of the apparatus, wherein the electrophotographic apparatus is provided in the conveying mechanism and detects rotation according to the amount of movement of the roll paper; It has a rotation detector that outputs a signal, and a timer that is activated by a change in the detection signal from the rotation detector, always counts from the beginning when activated, and counts up after a certain period of time if it is not activated, A roll paper presence/absence detection device for an electrophotographic apparatus, characterized in that it is configured to determine that there is no paper when it is detected that a timer has counted up without any change in the detection signal from the rotation detector.