JPH0438655B2 - - Google Patents

Description

Detailed Description of the Invention Technical Field The present invention relates to a jam detection device, and more particularly, to a jam detection device that detects a sheet at multiple points in a paper path and checks the conveyance state of the paper using a predetermined timing signal and detection state. The present invention relates to a jam detection device that detects the occurrence of a jam.

BACKGROUND TECHNOLOGY Generally, in copying machines, printing machines, etc., a paper detection mechanism detects paper being conveyed through a path within the device, and the state of paper conveyance is checked based on this detection state and a predetermined timing signal. When a jam occurs, the drive of the device is stopped to prevent secondary damage to the device.

Many specific systems for this kind of jam detection have been proposed or provided in the past, but in electronic copying machines in particular, expensive jam detection systems such as photoconductors, chargers, or heaters are located close to the paper path. Because the equipment is large and easily damaged, the sheet is detected at multiple points in the paper path from the paper feed section to the paper output section, and each detection point is checked to see if there is a jam. Efforts are being made to quickly deal with it in the event of an outbreak.

On the other hand, when a jam occurs in a copying machine, general users are able to remove the jammed paper and reuse the device.In order to process this efficiently, when a jam occurs, the power supply is immediately turned off and the device is stopped. In addition, there has been provided a system that distinguishes and displays in which part of the plurality of detection points the jam has occurred.

However, even if such an indication is made,
Since jamming is carried out by general users, it is possible that the jam paper may be forgotten to be removed, or a portion of the jam paper may be left in the passage without being removed. Furthermore, in relatively high-speed copying machines and the like, a plurality of sheets are conveyed back and forth in a passage, and even when a jam occurs, there is a possibility that sheets other than the jammed paper are present in the passage. In such a case, even if the jammed paper is taken out according to the jam position display, the user often does not notice other papers.

As mentioned above, if you restart the power supply and reuse the device with paper left in the path, the next paper may jam again or the equipment inside the device may be damaged. Conventionally, when the power supply is restarted after jamming, copying machines have been designed to immediately perform the same process as when the paper is jammed when the paper detection sensor detects the paper, or the paper conveyance system is operated for a certain period of time. There have been provided devices in which the remaining paper is ejected from the machine by driving the paper.

However, the method of stopping the device when paper is detected when power supply is resumed is useless if the paper is not jammed, and the method of driving the paper transport system for a certain period of time is If jam paper remains in the passageway, there is a risk of serious damage to the interior of the machine, and both pose many practical problems.

Purpose The present invention was made in view of the above points, and
When a jam occurs, the jam position is memorized, and when the power supply is restarted, it is detected whether or not there is paper in the passage, and when paper is detected, the detected paper is stored in the storage means. If the paper is in a jam position stored in the paper jam position, the control at the time of jam detection is continued, and if the detected paper is in a position other than the jam position stored in the storage unit, the paper transport unit is driven to remove the paper. The object of the present invention is to provide a jam detection device that can efficiently process jams without the risk of damaging mechanical equipment by controlling the discharge of jams. .

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 schematically shows an electrophotographic copying machine 1 as a mechanical device using the control system of the present invention, and first, its configuration and operation will be briefly explained.

A photosensitive drum 2 is rotatably supported approximately at the center of the main body of the electrophotographic copying machine 1, and around it are a charging charger 3, a developing device 4, a transfer charger 5, a separation charger 6, a cleaner 7, Static eliminators 8 are sequentially arranged, and a document (not shown) on a document table 9 is irradiated by a lamp 10 and a reflecting mirror
The images are projected onto the photoreceptor drum 2 through an optical system consisting of m ₁ , m ₂ , m ₃ and the lens 11, and are projected onto the photoreceptor drum 2 as the document table 9 moves and the photoreceptor drum 2 rotates. A toner image is formed.

On the other hand, the copying machine 12 is stacked and held at a predetermined position,
The sheets are fed one by one by the paper feed roller 13 in synchronization with the above image forming operation, are temporarily stopped by the intermediate roller 17 and the timing roller 18, and the image forming operation is performed by signals output as the optical system moves. The toner image is transferred to the transfer section by the transfer charger 5, separated from the photoreceptor drum 2 by the separation charger 6, and fixed by the fixing heat roller pair 14, 15, and then discharged. Exit 1
6 and the copying is completed.

Electrophotographic copying machine 1 having the configuration and operation as described above
uses a microcomputer with a timer function to control its operation, and the timer is set based on the program contents of the microcomputer and external signals output in conjunction with the copying machine operation, and the above-mentioned image forming and copying paper processing are performed. Performs sequence control of transportation, etc. When performing this sequence control, the electrophotographic copying machine 1 further includes a copy paper detection means 20 in the copy paper path PTL, and detects a jam in the copy paper 12 by sequentially detecting the copy paper 12 being conveyed. Has a function.

This jam detection function and its control method will be explained in detail below.

In the electrophotographic copying machine 1 described above, the detection units P ₁ , P ₂ , P ₃ and P ₄ on the copy paper path PTL detect the copy paper 1.
2 is detected. This checks for paper feeding errors on the _P1 copy, paper transport errors from the paper feed section to the transfer section on the _P2 copy, separation errors on the _P3 copy, and abnormalities in fixing and paper ejection on the _P4 copy. This is the part of a copying machine where copy paper jams are most likely to occur, and checking this part is sufficient to prevent damage to the internal mechanisms of normal copying machines due to jams. It is.

As shown in FIG. 2, each of the detection units P ₁ , P ₂ , P ₃ and P ₄ is provided with copy paper detection means 20 consisting of a light emitting diode LED and a light receiving element PS.
PTL is provided across the copy paper 12 depending on whether or not the light from the light emitting diode LED is detected by the light receiving element PS.
Detects the presence of.

The light emitting diode LED and the light receiving element PS are provided in the detection parts P ₁ , P ₂ , P ₃ and P ₄ respectively.
Represented by LED4 and PS1, PS2, PS3, PS4,
Figure 3 shows the relationship with the microcomputer MC.

Output ports PD1, PD2, PD3, and PD4 of the central processing unit (hereinafter simply referred to as CPU) in the microcomputer MC are resistors r1,
Transistors TR1, through r2, r3, r4
At the base of TR2, TR3, TR4, resistors r5, r
6, r7, r8 to ground VGG.

The collectors of transistors TR1, TR2, TR3, and TR4 are connected to light emitting diodes LED1, LED2, and LED2, respectively.
These light emitting diodes are connected to the power supply VSS through a resistor r9, and the transistors TR1, TR2, TR3,
When TR4 is turned on, a forward voltage is applied and light is emitted.

Light emitting diode LED1, LED2, LED3,
Light receiving elements PS1, PS2, each paired with LED4,
The power supply VSS is connected to the forward side of PS3 and PS4, and the opposite side is grounded through a resistor r10 and connected to the (-) side of the comparator IC1, and current flows in the opposite direction depending on the light receiving state. , the voltage produced by resistor r10 is input to comparator IC1.

The (+) side input terminal of comparator IC1 is connected to the power supply.
Voltage division (constant voltage) by VSS resistors r11 and r12
is input, and the output terminal OUT is connected to the base of the photodetection determination transistor TR5 via a resistor r13.

The emitter of the transistor TR5 is connected to the power supply VSS, and the collector is connected to the input terminal PA0 of the CPU and, together with the emitters of the other transistors TR1, TR2, TR3, and TR4, to the ground VGG via a resistor r14.

Furthermore, as shown in FIG. 3, the microcomputer MC has output ports PE0 and PE1 connected to a jam display section 30 and a jam counter 40, respectively, to display a jam in conjunction with a jam detection operation described later, and to mechanically determine the jam position. Display using a counter mechanism. Also, the battery was backed up.
The RAM 50 is connected to the RAM 50 by a bus line, and the jam occurrence block is identified according to the jam detection position and detection timing as described later.
Store at 0.

Next, the jam detection operation by the microcomputer MC will be explained using the flowcharts shown in FIGS. 4 to 6.

In FIG. 4, in the first block, feeding of the copy paper 12 is started with the start of the copying operation, and
A timer T-1 is set corresponding to the time required for the paper to reach the first detection point _P1 . The setting value of the timer T-1 changes depending on whether the upper or lower paper feeding section is selected.
Whether or not the leading edge of the copy paper 12 has reached the detection point _P1 within the time set by the timer T-1 is determined based on the level of the input port PA0 of the microcomputer MC. That is, the copy paper 12 reaches point P ₁ within time.
When it reaches , the light from the light emitting diode LED1 is blocked by the light receiving element PS1, so the output of the comparator IC1 becomes "1" (High level), and the output of the transistor TR5 becomes "1" (High level).
becomes non-conductive, and the signal level at input port PA0 becomes "0". If the copy paper does not reach point _P1 within the predetermined time due to paper feeding error or jam, the signal level of input port PA0 will remain "1", and when timer T-1 completes, jam J will occur. ₁ is determined. Regarding the identification of jam,
The following second to fourth blocks also have substantially similar processing and circuit operations.

Note that the light emitting diodes LED1 to LED4 are output ports PD0 to PD of the microcomputer MC.
Light is emitted by setting the output level of 3 to "1".

In the first block, after the copy paper 12 reaches the point _P1 , a signal is output with a slight time delay as the optical system moves or by a signal output by another timer means. Wait for intermediate roller 17 to be driven, thereby setting timer T-2. The timer T-2 is a timer for checking whether the copy paper 12 conveyed by the intermediate roller 17 reaches the detection point _P2 before the timing roller 18.

During the operation of timer T-2 in the second block,
The signal level of input port PA0 is determined, and if it becomes "0" within that time, it is normal, and if it remains "1", jam J2 is detected when timer T-2 completes. When it becomes "0", the timer T-3 is set after waiting for a drive signal for the timing roller 18 which is outputted in synchronization with the image forming operation on the photosensitive drum 2. Timer T-3 is the timing roller 18
This is a timer for checking whether the copy paper 12 conveyed by the photosensitive drum 2 or the like reaches the detection point _P3 .

In the third block, it is determined whether or not there is a jam based on the signal level of the input port PA0 while the timer T-3 is operating, and in this case, the timer T-4 is immediately set to "0". The purpose of the timer T-4 is to check whether or not the copy paper 12 is sent out from the fixing heat roll pair 14, 15 and reaches the point P4.

In the fourth block, the signal level of the input port PA0 is determined while the timer T-4 is operating, and if it becomes "0" within the time, the timer T-5 is set. After the leading edge of the copy paper 12 reaches point _P4 , the timer T-5 causes the copy paper 12 to reach the point P4.
This is a timer to check whether or not _P4 is passed. Therefore, the setting time of the timer T-5 is made variable depending on the length of the copy paper 12, or the time is set according to the maximum of the available copy papers.

In the fifth block, a jam is determined according to the signal level of input port PA0 during operation of timer T-5. In this case, the trailing edge of the copy paper 12 finishes passing the detection point _P4 within the time set by the timer T-5, that is, the signal level of the input port PA0 becomes "1" within the time, indicating normal conveyance.

FIG. 5 shows the process when a jam is detected.

When a jam is detected at any detection point, its jam status J1-J5 is identified, coded, and stored in RAM 50. RAM50
is backed up by a battery, and its memory contents are retained even if the power is turned off due to jam processing.

Next, the output port PE0 drives the jam display 30 to indicate that a jam has occurred, and the output port PE1 outputs the number of pulse signals corresponding to the jam position to display the jam counter 4.
Drive 0. The jam counter 40 is, for example, disclosed in Japanese Utility Model Application Publication No. 141946/1983 (Application No. 038518/1983).
As shown in Figure 2, the display section is variable by stepping in accordance with a predetermined number of input pulses, and the jam position is displayed separately, and the mechanical display retains the display even after the power is turned off. It has the advantage of being The display state of the jam counter 40 is determined by the signal level of the input port PB0 of the microcomputer MC, and the jam detection state of the microcomputer MC is not released until the display is reset. Next, stop power supply to the drive system,
Stop the drive means.

FIG. 6 shows the processing when the power is turned on.

When the power switch is turned on and the power supply is restarted in order to reuse the copying machine after removing the jam, in step #61, it is determined whether or not the above-mentioned jam counter 40 has been reset, and if it has not been reset, it is reset again. After executing jam processing such as displaying a jam, and if it has been reset, in step #62 output is output from output ports PD0 to PD3 to light up each light emitting diode LED1 to LED4 in turn, and to various detection points _P1 to _P4 . Check if paper exists. If there is no paper anywhere, the jam data in the RAM 50 is cleared in step #67 and the machine enters standby (ready for copying).

When paper is detected in the aisle, step #63
Then, the detection point is compared with the jam state stored in the RAM 50, and in step #64, it is determined whether the detected paper is jammed paper or not. That is, for example, if a jam is detected at detection point P ₂ (state J ₂ ), and if continuous copying is in progress, there is a possibility that non-jammed paper will be detected at point P ₄ in the check at step #62. There is. Further, if jammed paper is forgotten to be removed, it is detected at point _P1 . Similarly, if a jam is detected at point P ₁ , unjammed paper may be detected at point P ₃ or P 4, and if a jam is detected at point P 3, jammed paper may be detected at point P ₃ or P ₄ . If left behind, it is detected at point P ₁ or P ₂ , and what is detected at point P ₄ is not jam paper. Furthermore, if a tip jam is detected at point P ₄ (state J ₄ )
In this case, jam paper may be detected at point P ₃ , and other papers may be detected at point P ₁ .
In case of jam state _J5 , the jam paper is detected only at point _P4 .

Therefore, in step #64, it is determined whether or not the detected paper is jammed paper by comparing the jam state (stored in the RAM 50) with the paper detection point, and if it is jammed paper, the process proceeds to step #6.
If the paper is not jammed, the paper discharge process of step #65 is executed. The paper ejecting process refers to an operation in which the copy paper transport system other than the paper feed roller 13 is driven to eject the sheets remaining in the path to the outside of the machine. At this time, step #66
Now, a jam detection operation similar to that shown in FIG. 4 is executed from the detection point to confirm paper ejection.

When the paper is ejected, RAM50 is set in step #67.
Clears the jam data and enters standby mode.

In the above explanation, the specific jam detection mechanism and control are not limited to those of the embodiments,
For example, Japanese Patent Application Laid-open No. 55-096963 (Japanese Patent Application No. 54-096963
005418), jam detection may be performed for the leading and trailing edges of copy paper at each detection point. In this case, since the jam state differs depending on the detection point and whether it is the leading or trailing end, it is necessary to appropriately determine the conditions for comparison and determination in steps #62 to #64.

Further, the present invention is not limited to copying machines, but can be applied to general mechanical devices having paper feeding mechanisms such as printing machines and printers.

Furthermore, even when applied to a copying machine, the detection points and the accompanying jam status (identification of the jam position) shown in the above embodiments are merely examples; It may be set appropriately depending on the length and shape of the paper, the conveyance speed of the paper, etc.

Further, in the flowchart of the above embodiment, a timer for the next stage jam detection is set as paper is detected at each detection point. However, since the timer for jam detection only needs to be able to check the paper conveyance status at each detection point at the timing of the time-up, the timing of setting the timer itself is not a big problem, and it can be used in machines such as copying machines. The timer may be set appropriately in relation to the sequence control timing signal in the device. In addition, when correlating the length of the paper with the time-up timing of the timer, for example, as shown in Japanese Patent Laid-Open No. 134645/1983 (Japanese Patent Application No. 042937/1983), the paper size can be determined based on the sheet cassette installed, etc. A method can be adopted in which a signal corresponding to the sheet is acquired and a timer synchronized with the rear edge of the sheet is set using the signal.

Effects As explained above, the present invention is a jam detection device that detects a jam in a conveyance path in which paper is conveyed by a paper conveyance means from a predetermined paper feed port to a paper discharge port in a mechanical device, a paper detecting means for detecting the presence or absence of paper at a plurality of positions; a jam detecting means for detecting a paper jam from a detection state of the paper detecting means; a storage means for storing the jam detection position; and the jam detecting means. control means for stopping the paper conveyance means when a jam is detected by the paper; and when paper is detected by the paper detection means at the jam detection position stored in the storage means when power supply to the mechanical device is resumed; If the paper is not detected by the paper detection means at the jam detection position stored in the storage means, and the paper is detected at a position other than the jam detection position stored in the storage means, the control at the time of jam detection is continued. If a jammed paper is detected in the conveyance path, the initialization means controls the paper conveyance means to drive the paper to eject the paper. It is possible to prevent damage to the mechanical device by preventing the drive of the paper transport means, and to drive the paper transport means when paper related to the jam is not detected and paper not related to the jam is detected. This has an extremely useful effect in practice, in that it is possible to eject the paper out of the machine and save the effort of opening the machine and removing the paper.

[Brief explanation of drawings]

FIG. 1 is a sectional view schematically showing the configuration of a copying machine as an example of a mechanical device using the present invention, FIG. 2 is a diagram showing a specific example of paper detection in a paper path, and FIG. 3 is a control 4 is a circuit diagram showing the relationship between the microcomputer and mechanisms such as paper detection, and FIG. 4 is a flowchart showing the control procedure for jam detection.
FIG. 5 is a flowchart showing the processing when the jam occurs, and FIG. 6 is a flowchart showing the processing procedure when the power is turned on. DESCRIPTION OF SYMBOLS 1... Copy machine, 12... Copy paper, 20... Copy paper detection means, 50... RAM, MC... Microcomputer, _P1 , _P2 , _P3 , _P4 ... Paper detection point.

Claims (1)

[Scope of Claims] 1. A jam detection device that detects a jam in a conveyance path in which paper is conveyed by a paper conveyance means from a predetermined paper feed port to a paper discharge port in a mechanical device, the jam detection device comprising: a paper detecting means for detecting the presence or absence of paper at the paper detecting means; a jam detecting means for detecting a paper jam from the detection state of the paper detecting means; a storage means for storing a detected position of a jam; control means for stopping the paper conveying means when a paper transport means is detected; control is continued, and if the paper is not detected by the paper detection means at the jam detection position stored in the storage means, and the paper is detected at a position other than the jam detection position stored in the storage means. 1. A jam detecting device comprising: initializing means for driving a paper conveying means and controlling the paper to be ejected.