JPS60147752A - Copying machine - Google Patents

Abstract

PURPOSE:To control conveyance of copying paper by conveying the copying paper in such a way that the succeeding copying paper comes to a copying position after the copying paper is fixed with an image and is discharged to the outside in the stage of continuous copying and stopping the feeding of the succeeding copying paper when the copying paper after copying is jammed. CONSTITUTION:A CPU300 is used to control a copying operation and is connected to respective keys on an operation panel, for example, a key 301 for setting the number of copies, a print key PS, a clear stop key CS, a timing switch 52 for outputting an operation signal of a timing roller 24, a sensor 130 for detecting copying paper, a sensor 131 for paper discharge, etc. The processing by the CPU and the operation of the copying machine are synchronized during running of a motor. Respective steps are executed at the specified period regulated by an internal timer while the motor is in stoppage. If the copying paper after transfer is jammed during continuous copying, the copying paper to be conveyed next is stopped upstream of the transfer position and is thus prevented from being stuck with the toner. The transfer paper is reusable after the treatment of the jam. The waste of the copying paper is thus obviated.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a copying machine having a function of detecting a jam occurring in a copy paper conveyance path.

BACKGROUND TECHNOLOGY In general, in copying machines, printing machines, etc., a paper detection mechanism detects paper being conveyed through a path inside the device, and the state of paper conveyance is checked based on this detection state and a predetermined timing signal to prevent jams. □If this occurs, the drive of the device is stopped to prevent secondary damage to the device.

Generally, during continuous copying to obtain multiple copies from the same original, copy sheets are fed into a copying machine one after another.For example, one copy sheet after transfer is placed in a fixing device located downstream of the paper path During fixing, the next copy sheet has already been sent to the transfer section upstream on the paper path and the next transfer operation has started.

By the way, if a jam □ occurs in the fixing device downstream of the oil paper path or in its vicinity while continuous copying is being performed using the above-mentioned copying machine, the drive of the copying machine is stopped as described above, and paper feeding is stopped. The copy paper being transferred at the upstream transfer section has its transfer interrupted midway. Copy paper whose transfer is interrupted midway through has only a portion of the image transferred on it, so it is impossible to reuse it after clearing the jam, and it is discarded.

In this way, if a jam occurs near the fixing device downstream of the paper path during continuous copying, not only the jammed copy paper but also the
Even the copy paper on which normal transfer is being performed upstream becomes unusable, resulting in waste.

Purpose The present invention has been made in N-S to solve these problems, and its purpose is to prevent copying paper being transported upstream from jamming when a jam occurs downstream of the paper path during continuous copying. Our aim is to provide a copying machine that does not waste information.

Summary In order to achieve the above-mentioned object, the copying machine according to the present invention, during continuous copying, after the transferred copy paper has an image fixed by the fixing device and is ejected from the machine, the next copy paper is positioned at the transfer position. While the copy paper is being conveyed in such a way that a jam occurs on the copy paper after transfer.

Examples Examples of the present invention will be described below with reference to the drawings. , FIG. 1 shows an example of a copying machine according to the present invention. Approximately in the center of the copying machine body, a photosensitive drum (11) that can be rotated counterclockwise is installed, and around it is an eraser lamp (11).
2), a charging charger (3), a developing device (4), a transfer charger (5), a separation charger (6), and a cleaning device (force) are arranged.The photoconductor drum (1) has a photoconductor on its surface. The photoreceptor is uniformly charged by passing through the eraser lamp (2) and the charger (3), and receives image lightning from the optical system (10) to form an electrostatic latent on its surface. An image is formed.

The optical system (lO) is installed below the original glass (16) so that the original image can be scanned, and includes a light source (17), movable mirrors (11), (12), (13), and a lens (14).
It consists of a mirror (I5) and a mirror (I5). The light source (17) and the movable mirror (11) are connected to the photosensitive drum (1).
The movable mirror (12) moves to the left at a speed of (V/m) (where m: copy magnification) with respect to the circumferential velocity (V) (constant regardless of whether the magnification is the same or variable magnification).

(13) is driven to move to the left at a speed of CV/2m).

The electrostatic latent image is developed by the next developing device (4), and the toner image formed on the surface of the photoreceptor is developed by the timing roller (
24) etc., the image is transferred by the transfer charger (5) onto a copy paper conveyed in synchronization with this image forming operation.

The copy paper after the transfer is separated from the surface of the photoreceptor by a separation charger (6) and conveyed, and after the image is fixed by a fixing device (8), it is discharged onto a tray (9). On the other hand, the photosensitive drum (1) after the transfer is cleaned by a cleaning device (
7) The erase lamp (2) removes toner and charges remaining on the surface, and prepares for the next copying process.

Copy paper is stored in a removable cassette (20a) in the main body of the copying machine.
, (22a).

(22), and the paper feed rollers (20) and (22) of each paper feed section (20) and (22) are
21).

(23) is sent into the machine by being selectively driven.

The conveyance path for the copy paper sent into the machine, that is, the conveyance roller (30), the conveyance guide plate (31), and the timing roller (2)
4), conveyance bell) (32), in the conveyance path leading to the tray (9) via the fixing device (8) and the ejection roller (33), the copy paper is placed adjacent to and upstream of the timing roller (24). Detection sensor (130) and discharge roller (3
Discharge sensors (131) are provided adjacent to and downstream of 3).

The copying machine configured as described above is associated with a microcomputer system that controls each operation, as shown in FIG. 2, for example.

The CPU (300) controls the copying operation,
Each key on the operation panel of the copying machine (not shown), such as the numeric keypad (301) for setting the number of copies, the print key (
ps), clear stop key (fixed position switch (51) that detects the fixed position of the C5 input optical system (10), timing switch (52) that outputs the operation signal of the timing roller (24), copy paper detection sensor C130) It is also connected to a paper ejection sensor (131), etc., and is further connected to a decoder (30).
3) is connected to a display device (302) that displays the numerical value input using the numeric keypad (301) as the number of consecutive copies.

The CPU (300) also controls each motor in the copying machine,
It outputs operation control signals for the clutch, charger, etc., and controls the above-mentioned image forming sequence.

FIG. 3 is a flowchart generally showing the flow of control in cpu (300).

Step (#l) is executed when the power is turned on.
The process of initializing p u (300) is shown. Step (#2) is a subroutine that initializes the control state of the copying machine. Specifically, the number of copies is set to tl I II, the copy magnification is set to "1", and the electric lamp (light source) (17) is set to tl I II. A ROM that is pre-programmed as a standard state, such as setting the light intensity to "standard".
This shows the process of reading data from and setting it in RAM.

In step (#3), an internal timer is set to keep the processing time of the entire routine constant regardless of the processing content within the CPU (300).

Step (#4) is a routine for controlling copying operations such as charging, exposure, and development, and will be explained in detail later in FIGS. 4 and 5.

Step (#5) is to determine whether the copy paper fed into the copy machine from the paper feeder is ejected to the tray (9) outside the machine after image transfer and image fixation without jamming on the way. Perform processing for this purpose. Specifically, this will be explained in detail in FIG. 6 below.

Steps (#6), (jf7), and (#8) wait for the output of the step (motor pulse), and then step (#3).
).

As a result, the processing by the CPU (300) and the copying machine operation are synchronized while the motor is being driven, and when the motor is not being driven, the above steps are looped at a constant cycle determined by the internal timer. is executed.

FIGS. 4 and 5 are flowcharts showing an example of controlling the copying operation of the copying machine executed in step (#4).

In block IO, print switch (1'S)
When turned on, a copy start flag indicating that a copy operation has been started is set to +Vl''.

In block 11, the copy start flag is determined, and if the flag is 11, the flag is set to 110 //, and the main motor (not shown) that drives the photosensitive drum (1), the developing device (4) A developing motor (not shown), a charging charger (3), and a transfer charger (5) are activated, respectively, and a copy flag indicating that a copy operation is in progress and a motor pulse indicating that the motor is in operation are activated. Set the flag to 111〃, start the control timer (1''-A), and turn on the clutch of paper feed a; .

In block 12, the end of this timer (T-A) is determined and the paper feed clutch is turned off.

In block (13), it is determined whether the copying to be executed is the second copy of continuous copying (multi-copying) or fast copying, and if it is fast copying, the scanning optical system (lO) is driven. After the paper jam detection routine (described below) determines that there is no paper jam and the conveyance permission flag is set to 11'' and the copy is made, the scanning operation is started.Also, in order to prohibit conveyance of the next copy paper, the conveyance permission flag is set to 11''. Set it to ゝOI'.

In block 14, a switch (
52) is activated and a timing signal is output,
A process of turning on the clutch of the timing roller (24) and setting a timer (Jl) is executed. The copy paper is conveyed by the timing roller (24) in synchronization with the image on the photoreceptor drum (1).

Note that if a paper jam is determined in the jam detection routine described later during continuous copying and the conveyance permission flag is not set to 1, the scan signal will not be output in block (13), and therefore the optical system (10) will not be driven. . Also, if the optical system (10) is not driven, the switch (52)
does not operate and no timing signal is output.

Therefore, in the block (14), the timing roller (2
4) is not driven, and the next copy sheet stops upstream of the transfer position.

In block 15, the motor and timing roller clutch of the copy paper detection sensor (130) are turned off, and the timer (J2) and timer (J3) are set.

The timer (1” R) is set depending on the size of the copy paper used.
It may be set variably depending on the situation.

In block 17, when the optical system (10) returns to the home position due to the return operation and the home position switch 1) is turned on, the developing motor and transfer charger (5) are turned off and the timer (T -D), and furthermore, when continuous copying is completed, a copy flag indicating that a copying operation is in progress is set to 10, and during continuous copying, the copy flag is set to N1.

In block 18, it is determined that the timer (T-D) has expired, the main motor is turned off, and the motor pulse flag is set to 10.

Next, an example of jam detection control will be described using FIG.

In block 20, when the leading edge of the copy paper after image fixation is detected by the ejection sensor (131), the timer (Jl) for detecting the leading edge jam is reset, and the direction ejection sensor (131) detects the trailing edge of the copy paper. Then, the timer (
J2).

In block 21, a timer (Jl) and a timer (J2)
A jam is detected by sequentially determining the end of the process. The timer (Jl) is set to be slightly longer than the time it takes for the leading edge of the copy paper to be sent out by the timing roller (24) and detected by the ejection sensor (131), and is set to be slightly longer than the time it takes for the leading edge of the copy paper to be sent out by the timing roller (24) and detected by the discharge sensor (131). The timer (J2) is set at a time slightly longer than the time from when the trailing edge of the copy paper is sent out by the timing roller (24) until it is detected by the ejection sensor (131). (Jl), and is set at the timing when the timing roller (24) stops driving.
If step l) ends without being reset in block 20, it is determined that the leading edge of the copy paper has not been screamed out within the set time, that is, a jam has occurred at the leading edge of the copy paper,
The output from the microcomputer involved in the copying operation is turned off and the copying operation is stopped.

The same is true when it is determined that the timer (J2) has expired, and it is determined that a jam has occurred at the trailing edge of the copy paper, and the output from the microcomputer is turned off.

The block 22 determines the end of the timer (J3) set at the same time as the timer (J2) at the drive stop timing of the timing roller (24), and sets a conveyance permission flag "l" to permit conveyance of the next copy sheet. shall be.

The timer (J3) determines the timing for feeding the next copy sheet into the transfer unit after the trailing edge of the copy paper is ejected, so it ends at the same time as the trailing edge jam detection timer (J2). It may be.

Furthermore, even if the timer (J3) ends and the conveyance permission flag is set to ``1'', the next copy sheet is not transferred immediately (as mentioned above, the scanning is performed in block 13). The scanning motor that drives the optical system (10) is turned on to start the scanning operation, and the flock 14 is driven.Furthermore, even when the timing roller (24) is driven, the leading edge of the copy paper does not reach the transfer point. It is not transferred until it reaches the top of Yaja (5) (transfer position).Therefore, the timer (J
3) is the time it takes for the scanning optical system (10) to move after outputting the scan signal until the timing signal is output, and the time it takes for the leading edge of the copy paper to move to the transfer charger (5) in response to the timing signal.
1 (transfer position) can be set to be shorter than the sum of the timer (J2).

In addition, the timer (TA) explained in the above flowchart
, (Jl), (J2), (J3), (TR), (D), etc. are counted up to "1" in one routine of processing executed within the time specified by the internal timer. It is a programmed digital timer, and the time-up time is stored as numerical data.

As is clear from the above explanation, the copying machine according to the present invention has the following effects:
During continuous copying, after the copy paper after transfer has an image fixed by the fixing device and is ejected from the machine, the copy paper is conveyed so that the next copy paper is located at the transfer position, but the copy paper after transfer may be jammed. If a jam occurs, the conveyance of the copy paper is controlled so that the feeding of the next copy paper is stopped upstream of the transfer position. Since the copy paper conveyed to the transfer station is stopped upstream of the transfer position, toner does not accumulate on the copy paper, and after the jam is cleared, the copy paper stopped upstream of the transfer position can be used again. No paper wasted.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a schematic configuration of a copying machine according to the present invention;
Figure 2 is a circuit diagram showing the relationship between the microcomputer system that controls the copying machine and various input switches and displays.
FIG. 3 is a flowchart generally showing the processing in the CPU, FIGS. 4 and 5 are flowcharts showing details of the processing in the copying operation control routine, and FIG. 6 is a flowchart showing details of the processing in the jam detection routine. . 1... Photosensitive drum, 4... Developing device, 5... Transfer charger, 8... Fixing device, 24... Timing roller, 33... Discharge roller, □ 131...
Copy paper detection sensor, 131...discharge sensor, applicant
Minolta Camera Co., Ltd. Figure 1 Figure 2 30θ Figure 5 Figure 6

Claims (1)

[Claims] 1. A means for detecting the discharge state of the copy paper provided near the discharge position of the copy paper, and a small signal and a jam detection timing signal from the means for detecting the discharge state of the copy paper. means for detecting a jam of the copy paper from the preceding copy paper; means for temporarily stopping the copy paper upstream of the transfer position and feeding the copy paper to the transfer position in response to a re-conveyance start timing signal; A copying apparatus characterized by comprising: means for outputting a timing signal to start re-conveying the next copy sheet to the transfer position so that the leading edge of the next copy sheet does not reach the transfer position at the trailing edge jam detection timing. Machine.