JPS63171744A - Paper feeder - Google Patents

Abstract

PURPOSE:To make a paper jam easily handleable, by installing a sensor, detecting the paper jam, in a passing route of paper to be fed out of a cassette for a copying machine or the like, and when detecting the jam, making the paper so as to be put back in the cassette. CONSTITUTION:A cassette 2 is detachably attached to a paper feeding part, and paper P is delivered piece by piece by a paper feed roller 3 and an intermediate roller 4. The delivered paper is once stopper in the state that its tip comes into contact with a timing roller 5 and then it is fed by this timing roller 5 synchronously with rotation of a sensitized drum 7, whereby a toner image on this drum 7 is transferred, and it is separated from the sensitized drum 7. In a passing route of the paper P, there are provided with sensors PS1 and PS2 for detecting a jam of the paper P, and when the jam is detected by these sensors PS1 and PS2, the paper feed roller 3 is rotated and driven in the reverse direction, thus the paper P is made so as to be put back in the cassette 2.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is a method for feeding paper stored in a cassette attached to a paper feeding unit of a copying machine, a laser printer, etc. one by one using a rotationally driven paper feeding roller. The present invention relates to a paper feeding device that feeds paper, and particularly relates to a paper feeding device that facilitates handling when a paper jam occurs.

(Prior art and its problems) Conventionally, in devices such as copying machines, laser printers, and microleague printers, paper stored in one or more cassettes installed in the paper feed section of these devices is rotated and driven. A paper feeding device is provided that feeds out one sheet at a time using a paper feeding roller. In such paper feeding devices, jams often occur, in which the fed paper gets wrapped around a reroller that gets caught on the way and does not flow properly, but the process when a jam occurs is generally troublesome. .

For example, if a jam occurs in a copying machine,
In order to remove the paper that caused the jam, it was necessary to open the front door of the copying machine or to open the upper unit, which was a cumbersome task. In copying machines, jams occur in the paper feed section, transfer section, or fixing section, but the occurrence rate of jams in the paper feed section is low because it is affected by the cent condition of the paper in the cassette, the amount of paper remaining, etc. This is relatively expensive, and it has been an important issue to facilitate the handling of jams in the paper feed section.

(Means for Solving the Problems) In view of the above-mentioned problems, it is an object of the present invention to provide a paper feeding device that can easily handle paper jams when they occur. The technical means for this purpose is, for example, as shown in FIGS. 1 to 4, a paper feed roller 3 that rotationally drives the paper P stored in a cassette 2 installed in a paper feed section of a copying machine or the like. The paper feeding device l is configured to feed out one sheet at a time, and sensors PS1 and PS2 are provided in the passage path of the paper P fed out from the cassette 2 to detect paper jams, This apparatus is characterized in that when a paper jam is detected by the sensors Psi and PS2, the paper feed roller 3 is rotated in the opposite direction to return the paper to the cassette 2.

(Example) The present invention will be explained below based on illustrated embodiments.

Fig. 1 shows a paper feeder 1 installed in the paper feeder of a copying machine, Figs. 2 and 3 show a state in which a jam has occurred in the paper feeder 1, and Fig. 4 shows a state after a jam has occurred. Indicates processing status. In these figures, 2 is a cassette in which paper P is stored, 2a is an opening/closing lid of cassette 2, 3 is a paper feed roller, 4 is an intermediate roller, 5 is a timing roller, and 6 is a pressure roller for pressing paper P onto paper feed roller 3. 7 is a photosensitive drum, 8 is a transfer charger, 9 is a separation charger, and Psi and PS2 are sensors for detecting paper. Although not shown, cassette 2
is provided with a jam removal switch that is activated by opening the opening/closing lid 2a.

In FIG. 1, a cassette 2 is removably attached to a paper feed section, and a sheet of paper P is fed by a paper feed roller 3 and an intermediate roller 4, which are rotated at appropriate timings according to the copying operation of the copying machine. sent out one by one. The fed paper P temporarily stops and waits with its leading edge in contact with the timing roller 5, and then is fed out by the timing roller 5 in synchronization with the rotation of the photoreceptor drum 7.
The toner image on the photoreceptor drum 7 is transferred at a transfer position of the transfer charger 8 and separated from the photoreceptor drum 7 by the separation charger 9 . Thereafter, the image is fixed by a fixing device (not shown) and then the paper is ejected.

FIG. 5 shows the arrangement of the operation keys on the operation panel of the copying machine.The operation panel 70 includes a print key 71.7 segments) for starting the copying operation
A numeric display device 72 configured with 1, 2, . ...Numeric keypad 8 corresponding to the number 9.0
0 to 89, a clear/stop key 91, up and down keys 93 and 94 for changing and specifying the copy image density in steps, a jam display section 73 for indicating that a jam has occurred, and a jam display section 73 for indicating the location where a jam has occurred. Each display section 7 shown
4 to 77 are provided.

FIG. 6 shows the control circuit of the copying machine, and 201 is the first CPU.
, 204 is a switch matrix formed by keys etc. on the operation panel, and 207 is a decoder. Note that the output terminals AI to A7 are connected to each motor, each roller clutch, each drive switching transistor of each charger, or a power supply circuit (not shown) of the copying machine. The aforementioned paper feed roller 3, intermediate roller 4, timing roller 5, photosensitive drum 7, etc. are controlled by the first CPU 201.

FIG. 7 schematically shows the overall configuration of the processing of the first CPU 201. When the program starts, first, in step S1, a subroutine for initializing the CPU 201 and the copying machine is executed.

In step S2, the internal timer of the first CPU 201 is set, and then in step S3, the sensors PS1 and PS2
, and data of various switches inside the copying machine A are input.Next, in step S4, it is determined whether or not the state is ready for copying.If possible, in step S5 normal copy control (in the standby state) is performed. ), and if not possible, perform abnormality processing in step S6. Then, in step S7, control signals, display signals, etc. are output, and in step S8, abnormal state, toner empty, paper empty, etc. After detecting the state of the copying machine, and finally counting up the control timer in step S9,
At step 310, one routine ends after waiting for the internal timer to end.

FIG. 8 is a flowchart showing details of the state detection routine of step S8 shown in FIG. 7, focusing on jam detection in the paper feed section.

First, in step 520, it is determined whether the state indicating the state of the paper P or the jam processing state is "01", and if it is "@O", then in step S21, the paper feed roller 3
It is determined whether or not the timer Tl is on, and if it is on, the timer Tl is turned on in steps 322 to S24.

Cent T2 and set the state to 11''.

The timers TI and T2 are counted inside the first CPU 201. When the state is 1'' in step 325, jam 0 is detected in steps 326 to 331. That is, the timer T1 ends in step S26. If the sensor PS1 does not detect the paper P by then, the sensor PS performs the jam O processing as a jam 0.
If there is paper in 1, reset the timer T1 and set the state to "2".9 Next, if it is determined in step S32 that the state is 2", steps 333 to 34
In other words, if the sensor PS2 detects the paper P before the timer T2 ends, the timer T2 is reset in step S41, and the process in step 3 is performed.
At step 42, the state is set to "O".

If the paper P is not in the sensor PS2 but is in the sensor P51 (the state shown in FIG. 2 or 3), step S
35, the copying operation is stopped, step S36 is to release the pressure on the paper P by the lever 6 as shown in FIG. (the state shown in FIG. 4), set the timer T3 (T3 automatically counts), and set the state to 3'. Step S
If there is no paper P in sensor PS1 at step 34, step 345. In step 346, the jam 1 is processed as a jam 1, and the state is set to "θ".

When the state is "3', step 343.S4
4, it is detected whether or not there is paper in the sensor PS1 by the end of the timer T3, and if there is, it is treated as a jam 1, and if there is not, it is treated as a jam 0, and the state is set to "0".
Make it.

In these processes, the timer T1 is set for a time sufficient for the paper P to be fed out from the cassette 2 in a normal state by the paper feed roller 3 to activate the sensor PS1, and the timer T2 is set for a time sufficient to operate the sensor PS2 in the same manner. The timer 73 determines the sufficient time required for the paper P to return to the cassette 2 due to the reverse rotation of the paper feed roller 3 from the state where the paper P is present at the sensor psi, and disappear at the position of the sensor PS1. Each is set. To dispose of jam 0, open/close lid 2 of cassette 2.
This is done by opening a and activating a reset switch (not shown). Note that when opening the opening/closing lid 2a, the paper P in the cassette 2 should be returned to its normal state, or the paper P should be confirmed to be in its normal state.To dispose of the jam 1,
This is done by opening the front door of the copying machine main body, removing the jammed paper inside while referring to the display sections 74 to 77, and then pressing the reset switch located inside the front door.

Therefore, if the paper P in the cassette 2 is sent out by the rotation of the paper feed roller 3 and the paper P does not reach the position of the sensor PS1 even after the timer TI has elapsed, the jam is 0, and the paper P does not reach the position of the sensor PS1 within the timer TI. P
When the paper P reaches the position S1 but does not reach the position of the sensor PS2 even after the time of the timer T2 and there is no paper P at the position of the sensor Ps1, a jam 1 occurs.

If the paper P does not reach the position of sensor PS2 after the time set by timer T2 and still remains at the position of sensor PS1, the paper feed roller 3 and intermediate roller 4 are reversely rotated to move the jammed paper toward cassette 2. Return to
As a result, if there is no jammed paper at the position of the sensor PS1 within the time set by the timer T3, the jam is 0, and if there is any jammed paper at the position of the sensor PS1 even after the time set by the timer T3, the jam is 1. Note that the paper feed roller 3
When the intermediate roller 4 is rotated in the reverse direction, the timing roller 5 and the photosensitive drum 7 may be kept in a neutral state where they can freely rotate.

Therefore, sensor PS1 is activated and sensor PS2 is activated.
If the jam paper is in a position that does not activate the
Conventionally, troublesome jam processing had to be performed as jam 1, but according to the above embodiment, the jam is automatically sent back into the cassette 2, and jam 0 is easily processed.
In other words, there is no need to perform inspection operations on the copying machine itself (all you have to do is open and close the opening/closing lid 2a of the cassette 2 and check the paper P in the cassette 2. If the paper is not successfully returned to the cassette 2, it is necessary to treat it as a jam 1.

According to the above embodiment, jams in the paper feed section can be easily handled in most cases by inspecting the cassette 2, and by opening the front door of the copying machine or lifting the upper unit. There is no need to perform cumbersome work such as opening the door, which greatly reduces the burden on the user.

In the above-described embodiment, the position of the jammed paper when returning the jammed paper to the cassette 2 may be changed. The sensors Psi and PS2 may be provided at other positions, and the number of sensors Psi and PS2 may be increased or decreased. The intermediate roller 4 may be omitted or added. In the above embodiment, the cassette 2 is a single-stage type. Although a two-stage type, a three-stage type, or a manual feeding type is described above.

The flow of state detection described above can be changed as appropriate.

In the above-mentioned embodiment, when handling jam 0, the reset is performed by opening the opening/closing lid 2a of the cassette 2 and activating the reset switch. It may be reset by pulling it out, or by any other suitable reset switch, or it may be reset automatically.

(Effects of the Invention) According to the present invention, since jammed paper is returned to the cassette, it is possible to easily handle the jam when it occurs.For example, a reset switch activated by the opening/closing lid of the cassette If this is provided, it is possible to clear the jam by opening the opening/closing lid and returning the paper in the cassette to a normal state. The troublesome work of raising the unit will be greatly reduced.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a side view showing an embodiment in which the paper feed device of the present invention is provided in the paper feed section of a copying machine, and FIG.
3 and 3 are side views showing a state in which a jam occurs in the paper feeding device shown in FIG. 1, FIG. 4 is a side view showing a processing state after a jam occurs in the paper feeding device shown in FIG. 1, and FIG. is a plan view showing the structure of the operation panel of the copying machine, FIG. 6 is a block diagram showing the structure of the control device of the copying machine, and FIGS. 7 and 8 are flowcharts showing the processing procedure executed by the first CPU. be. l...Paper feeding device, 2...Cassette, 2a...Opening/closing lid, 3...Paper feeding roller, 4...Intermediate roller, P...
·paper.

Claims (1)

[Claims] A paper feeding device that feeds papers stored in a cassette attached to a paper feeding unit of a copying machine one by one using a rotationally driven paper feeding roller, the paper feeding device feeding the paper stored in a cassette installed in a paper feeding unit of a copying machine or the like one by one. A sensor for detecting a paper jam is provided in the passage path, and when the sensor detects a paper jam, the paper feed roller is rotated in the opposite direction to return the paper to the cassette. A paper feeding device characterized by: