JPS5975263A - Controlling method of copying machine - Google Patents

Abstract

PURPOSE:To obtain an excellent copy sheet free of a picture breakdown by transferring toner which is not transferred and remains on an image carrier surface to copying paper and then controlling to clean when a paper source is turned on after a jam is removed. CONSTITUTION:If a jam occurs, an instruction JAMP.JAM is written in an address 00 of an RAM in a micrcomputer. When the jamming paper is removed and the power source is turned on again, the program counter of the CPU in the MC indicates the address 00 where the instruction for a jump to an address JAM is stored, so a photosensitive drum 2 is driven; and an image formation start point A is detected by a sensor S and transmitted to the MC, which advances to copying operation. Then, the copying paper is fed into a machine and a transfer part transfers a toner image which is not transferred to the copying paper at all and remains on the surface of the photosensitive drum 2 in case of the jamming or due to a deficiency of transfer to the copying paper, thus reducing the toner. Consequently, cleaning operation is carried out normally without placng a load on a cleaning device 9.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a method of controlling a full-length copying machine, and more particularly, to a method of controlling a copying machine of a type in which an image carrier is rotated for a predetermined period of time when the power is turned on.

BACKGROUND ART In general, in a copying machine, in order to keep the light sensitivity of the photoreceptor drum as an image carrier constant, after turning on the power and before starting the copying operation with the print switch, the photoreceptor drum is turned on with the eraser lamp turned on. It is known that the drum is rotated for a predetermined period of time, and the surface of the photoreceptor drum is sometimes cleaned during this rotation.

However, when using magnetic toner and after transferring the toner image formed on the surface of the photoreceptor drum onto copy paper, cleaning the toner remaining on the surface of the photoreceptor drum using a magnetic brush cleaning device has the following disadvantages. arise.

Now, if a jam occurs in the copying machine during copying, the power to the copying machine is turned off to stop the copying machine, but at this time, if the copy paper has not reached the transfer section or if the copy paper is in the middle of the transfer In some cases, a portion where the toner image on the surface of the photoreceptor drum is not transferred at all to the copy paper and remains, ie, an untransferred portion, or a portion where the toner image is insufficiently transferred, ie, a defective transfer portion, is formed.

Then, when the jam is cleared and the power is turned on again,
Even if the photoreceptor drum is rotated for a predetermined period of time to clean the residual toner on the surface of the photoreceptor drum as described above, the residual toner in the untransferred areas and defective transfer areas is not affected by the electrostatic attraction force of the transfer charger. Therefore, the electrostatic adsorption force of the toner remaining on the surface of the photoreceptor drum without being transferred is stronger than when the transfer charger is applied. Therefore, even if the magnetic brush is brought into sliding contact with the surface of the photoreceptor drum and the residual toner is magnetically attracted, the residual toner in the untransferred area or the defective transfer area is not completely absorbed by the magnetic brush and is removed from the photoreceptor drum. Leave it on the surface and shake it off.

In this way, residual toner on the surface of the photoreceptor drum is not completely cleaned and removed by the magnetic brush cleaning device, resulting in poor charging, which adversely affects electrostatic latent image formation, and uneven development and poor transfer, resulting in unsatisfactory results. I can't get the copy sheet I can.

Objective/Summary To solve the above-mentioned inconveniences, the present invention provides a powder image transfer type electronic copying machine that is equipped with a means for detecting a jam in the copying machine and a means for releasing the jam, and that rotates an image carrier for a predetermined period of time when the power is turned on. , when the jam is cleared and the power is turned on, the toner remaining on the surface of the image carrier without being transferred is transferred to the copy paper, and then the jam is controlled to be cleaned. When the toner remains on the image 48 without being transferred to the copy paper at all, or the toner remaining on the surface of the image carrier due to transfer failure, normal copying operation is resumed after the power is turned on again after clearing the jam. It is an object of the present invention to provide a method for controlling a copying machine, which can clean and remove all residual toner on the image carrier at the start of copying and obtain a good copy sheet without image defects.

Example The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram of a copying machine (1) using the control system of the present invention, and first, the structure of the copying machine (1) and the outline of the copying operation will be explained with reference to this figure.

A photoreceptor drum (2) is supported at approximately the center of the wooden body of the copying machine (1) so as to be rotatable in the counterclockwise direction in the figure, and around it are an electrostatic charger (3) and a focusing light transmitter. Optical system (4) consisting of an array, etc., between developer bags (5), transfer charger (6), minute PTT charge 1-(7), supply eraser lamp (8), magnetic brush cleaning device (9), main laser lamp (10) and Yanzer (S), etc., which detect when the image forming start point (A) of the photoreceptor drum (2) has reached its original position again, are arranged in sequence, and the photoreceptor drum (2) As it rotates, its surface is sequentially subjected to processes such as charging, exposure, and development, and a toner image is transferred onto a copying paper (P) that is synchronously conveyed, thereby making a copy.

Here, the cleaning device (9) is generally composed of a magnet (MG) provided within a rotatable sleeve (90).

The copy sheets (P) are stacked and held in the case 7 (20), and are pushed up against the paper feed roller (23) by pushing up the middle plate (22) with the push-up member (21), and the paper feed roller It is fed along with the rotation of (23). The pushed-up copy paper (P) is detected by a paper detection switch (SW, ), and when the copy paper (P) runs out, the paper detection switch (SW, ) is turned off to prevent the start of the copying operation. The copy paper (P) fed into the machine is superimposed on the image on the drum (2) at the transfer section, the toner image is transferred by the transfer charger (6), and the toner image is transferred to the drum (2) by the separation charger (7). 2) and is discharged onto a tray (27) via a conveyor belt (24), a fixing device (25), and a discharge roller (26). The copy paper (P) is detected by a jam detection switch (SW2) provided near the timing roller (TR) and a jam detection switch (SW2) provided near the entrance of the conveyor belt (24).
A timer mechanism (described later) checks the conveyance state of the copy paper (P), and if the copy paper (P) is not normally conveyed within a predetermined time set by the timer, a jam is determined.

A document (not shown) is placed on a document tray (28) that is supported reciprocally on the top surface of the copying machine main body, and is illuminated from the bottom by an exposure lamp (29). ) is scanned, and the original image is transferred to the photoreceptor drum j, (2) via the optical system (4).
) to project onto a surface.

FIG. 2 is a diagram showing the operation/control unit (30) of the copying machine (1), in which (31) is the print switch that starts the copying operation, (32) is the @ number key for setting the number of copies, ( 3
3) is the jam indicator, (34) is the cassette), when there is no copy paper (P) in the cassette (20),
0) is not inserted in the specified position, the empty display section (35) displays the set number of copies, and the number display section (36) displays the number of copies subtracted for each copy.
) is the power-on display section.

FIG. 3 shows a block diagram for control according to the present invention.

In the figure, MC is a microcomputer that controls the operation of the copying machine (1), and provides output to mechanical loads such as a motor, flanch, charger, lamp, and various display outputs.

The photosensitive drum (2) is connected to a drive source (not shown), and the rotation drive 0j of the drive source is controlled by a main motor drive control circuit (40) connected to a micro corned beef (MC).

In this embodiment, when the copying machine (1) is powered on by a main switch (not shown), an auto-shut timer (
AST) made 11L, this auto shut timer (A
ST) is operating, the main motor control circuit (40) rotates the photoreceptor drum several times with the main eraser lamp (10) turned on in order to keep the light sensitivity of the photoreceptor drum constant. Then, the photosensitive drum (2) is stopped at a position where the image formation starting point (A) faces the sensor (S). At this time, the charger (3), the developing device (5)
), the transfer/separation chargers (6) and (7) are off, but the surface of the photosensitive drum (2) has been cleaned by the cleaning device (9).

Further, at the same time as the power is turned on, a heater for the fixing roller (not shown) provided in the fixing device (25) is turned on, and the power-on display section (3) is turned on until the fixing roller reaches a predetermined temperature.
6) Turn on the ``Queit display''. When this "quiet display" is canceled, reception of the print switch (31) is permitted, but the print switch (31)
When one copying operation is started, the photosensitive drum (2
) performs image formation by rotating several times, and after the image formation is completed and the copy paper (P) that has been copied is discharged to the tray (27), the image formation starting point (A) is located at the sensor (S). The photoreceptor drum (2) stops at a position facing the.

A magnet roll (MR) provided in the developing device (5) is connected to a developing motor (not shown),
The rotational drive of the developing motor is controlled by a developing motor drive control circuit (41) connected to a microcomputer (MC).

The charger (3) uniformly corona charges the surface of the photoreceptor drum (2) by applying a voltage from a high-voltage power supply (not shown). It is controlled by a connected charging control circuit (42).

9- Also, the transfer and separation charger (6), (7) Ii
A transcription machine connected to a microcomputer (MC)
A separation control circuit (43) controls on/off of applied snow pressure.

In general, the microcomputer (MC) performs control such as jam determination.

Now, if a jam occurs in the copying machine (1), the copying operation of the copying machine (1) will immediately stop due to the jam signal output from the jam detection circuit (44). The control according to the present invention will be explained with reference to the flowcharts in FIGS.

First, Figures 4 and 5 are flowcharts for detecting a jam in the copying machine (1).
When the power is turned on to [), initial settings are performed in step ■. The initial setting is the number “1” on the copy number display (35).
．． The microcomputer (MC) memory (not shown) performs processing such as setting the exposure light amount to the standard state.
This is executed using data stored in the computer.

In this step, processes such as clearing the memory, setting various flags to "0" and resetting a timer are also performed.

In step (2), an internal timer set in the microcomputer (MC) is set. The internal timer is used to define one routine of microcomputer (MC) processing.

In step (2), manual scanning of keys such as the numeric keys (32) is performed, in step (2), output is made for all loads, and in step (2), output is made for all loads.

In step (2), the state of the print switch (31) is determined, and if it is not on, the process proceeds to step 0, and if it is on, it is determined in step (2) whether or not it is the rising edge of the print switch (31). When the print switch (31) is turned on, that is, when it is determined that it is on for the first time in the routine being executed, the state of the paper detection switch (SW, ) is l! at step (3). 11 separated SW, =
1, that is, if the copy paper (P) is detected, the copy flag (F) is set to "1" in step 2 and the photosensitive drum (2) is
At the same time as starting a copying operation such as rotation of the
A timer (TA) is set to specify the timing for turning on the timing roller (TR). In step 0, processing of other switch inputs is executed.

When the copy flag (F) is "1" in step 0, the counting process of the above-mentioned timer (TA) is executed in step 0, and the end of the timer (TA) is determined by l'lJ in step 2. do.

When the end of the timer (TA) is determined in step ■, the timer (T-B) for detecting a leading edge jam is activated.
Set the jam detection switch (8w2) in step 0.
) is determined, and if (8w2) = 1, the process proceeds to processing step (2) for copying operations such as turning on the drive of the timing roller (TR), and if (SW2) = 0, it is determined that a jam has occurred and will be described later. Jam processing control is executed.

In step O, the end of the copying operation is determined, and in step 2, the display on the sheet number display section (35) is subtracted.
In step @, as a result of the subtraction, it is determined whether or not the set number of copies have been completed.If the set number of copies has been completed, the copy flag (F) is set to "0". The leading edge jam detection process of the copy paper (P) by the detection switch (SW3) is shown.

The timer (T-B) is set at the end of the timer (TA), that is, when the timing roller (TR) starts driving, and the leading edge of the copy paper (P) is set to the jam detection switch (SW3).
) is reached and time-up occurs. Therefore, step @
When it is determined that the timer (T-B) has timed up in step [phase], if the switch (SW3) is not "1" in step [phase], a jam is determined as l'l+, and the jam processing control is executed.

In this way, when a jam is detected by the jam detection switch (8w2), the toner image formed on the surface of the photoreceptor drum (2) is not transferred to the copy paper (i゛) and is completely transferred to the photoreceptor drum. (2) Will remain on the surface. On the other hand, if a jam is detected by the jam detection switch (SW3), the transfer charger (6) will be turned off during the transfer, which will prevent the toner image from being transferred to the copy paper (P) at all. There are also areas where the toner is insufficiently transferred, and a large amount of toner remains on the surface of the photoreceptor drum (2).

Note that in this embodiment, jam detection is also performed by a jam detection switch (not shown) provided near the fixing device (25), but when copy paper (P) is detected by this jam detection switch, , since almost all of the toner image has been transferred, there is no problem as in the conventional method, so a detailed explanation will be omitted.

-1- The timers (T-A) and (T-B) are digital timers that are programmed to count up for each routine of microcomputer (MC) processing, and the count is stored in the memory. is stored in advance as numerical data.

Control procedures such as ``2 series'' are stored in the main program as a read-only memory IJ in the microcomputer (MC).
(ROM) (not shown),
When a jam occurs, jam processing control is executed according to the control procedure shown in Figure 6 and Figure 14-7.

When a jam occurs in the copying machine (1), step O is executed to turn off the load outputs of the motor, charger, lamp, heater, etc., and stop copying. Step @
Now set the internal timer that specifies the length of the jam removal immediate routine, and in step [phase] set the jam indicator (
33) Control the display output such as lighting the lamp, and in step 1, write the command ``JAMP JAMJ (!l:)'' to the address ``00'' of the random access memory (RAM) in the microcomputer (MC). is written, waits for the end of the internal timer in step ■, and returns to step ■.This state continues until the jammed paper is removed from the copying machine (1) and a jam reset means (not shown) is operated.Here, When removing jammed paper from inside the machine, the power to the copying machine is turned off by a safety switch (not shown), but since the random access memory (RAM) is backed up by a battery, "JAMP JAM" is stored in the address 100. instructions are memorized.

When the jammed paper is removed, the jam is cleared by a reset means (not shown), and the power is turned on again, the program counter (PC) of the central control unit (CPU) in the microcomputer (MC) becomes the address 00, r
Execute the command at address oo. In step ■,
The command at "address 00" is the command "go to JAM address", so the program command at "JAM address" is executed.

In Step @, the auto-shut timer (AST) that operates when the power is turned on is turned off, and in Step [Co., Ltd.], the charge control circuit (42) controls the charger (3).
), the transfer/separation control circuit (43) turns off the voltage application to the +li, z transfer/separation chargers (6), (7), and step (3) turns off the high voltage application to the developing The motor drive control circuit (41) turns off the rotational drive of the magnet roll (MR) and stops the development. Furthermore, in step 1, the main erase lamp (10) is turned on. In this state, in step @, the main motor IIX control circuit (40) drives the main motor (not shown) to control the body drum (7).
2) is driven to rotate. At the step d mountain, the image forming start point (A) of the 11 thermophotonic drum (2) is connected to the sensor (S).
is detected by the microcomputer (
MC), in step [phase] the transfer/separation control circuit (43) transfers the transfer/separation charger (6),
(7), then turn on the paper feed roller (32) (@
1) (see Figure 1). Copying operation processing step 6, such as turning on the squirrel motion, feeds the copy paper (P) toward the inside of the machine, and in the transfer section, when a jam occurs, the copy paper (P)
The toner image remaining on the surface of the photoreceptor drum (2) without being transferred at all to the surface of the photoreceptor drum (2), or rather, the transfer being insufficient. 6) Transfer it to copy paper (P). By transferring the remaining toner image onto the copy paper (P) in this way, the amount of remaining toner on the surface of the photoreceptor drum (2) can be reduced.
9) The burden is 17- The cleaning action can be performed normally.

In step [phase], the random access memory (RA
Write an instruction to return to the "address 00" domain program of M), that is, an rJAMP MATNJ instruction.

When the jam processing control procedure is completed as described above, "address 00" is loaded into the program counter (PC) in the central control unit (CPU), and in step (2), the command at "address 00" is executed, that is, The command "Go to MAIN address" jumps to the main program shown in FIGS. 4 and 5, and normal control is executed.

” In the first embodiment, the photoreceptor drum (2
), when the image forming starting point (A) is rotated by the sensor (
Although the control is performed so that one copying operation is performed after being detected by S), if the photosensitive drum (2) has a relatively small diameter, the drive of the paper feed roller (23) is turned on immediately after the power is turned on again. Even if the remaining toner image is transferred to the copy paper (P) by performing copying operations such as The amount of residual toner can be reduced, and normal cleaning can be performed without putting a burden on the cleaning device.

Still, in the embodiment described in -1-, the magnet (MG) in the sleeve (90) of the magnetic brush cleaning device (9) is
The magnetic brush can be changed to a position where the poles of the magnet (MG) face the surface of the photoreceptor drum (2) and a position where the gap between the poles of the magnet (MG) faces the surface of the photoreceptor drum (2). A magnet (MG) is located at a position where it contacts the surface of the photoreceptor drum (2), and when not cleaning, the magnet (MG) is placed in contact with the surface of the photoreceptor drum (2).
The gap between the poles of the magnetic brush (MG) is made to face the surface of the photoreceptor drum (2) so that it comes into close contact with the surface of the photoreceptor drum (2), and the copy paper (P) is placed near the 111ff charger (7). A separation detection sensor is provided to detect whether or not the photoreceptor drum (2) has been reliably separated from the photoreceptor drum (2). and,
-4 When executing the jam processing control described in Section 2, the magnet (M
The magnetic brush cleaning device (9) is placed in a non-cleaning state with the pole gap of G) facing the surface of the photoreceptor drum (2), and the image formation starting point (A) passes through a position facing the sensor (S). Later, when the 11[f] delivery detection sensor is reached, if the magnetic brush cleaning device (9) is set to the cleaning state by placing the magnet (MG) facing the surface of the photoreceptor drum (S), the photoreceptor drum (2) The residual toner on the second surface is transferred to the copy paper (P) during the jamming process and is cleaned.

Furthermore, although a magnetic brush cleaning device was used as the cleaning device in the embodiment described in ``-'', almost the same effect can be obtained even when a fur brush cleaning device is used.

Effects As is clear from the above description, the present invention provides a powder image copying electronic copying machine that is equipped with a means for detecting a jam in the copying machine and a means for clearing the jam, and that rotates an image carrier for a predetermined period of time when the power is turned on. , when the jam is cleared and the power is turned on, the toner remaining on the surface of the image carrier without being transferred is transferred to the copy paper and then the cleaning is performed. Toner images that are not transferred to the copy paper at all and remain on the surface of the image carrier -F and toner images that remain on the surface of the image carrier due to transfer failure are cleared, and normal copying operations begin after the power is turned on again. The residual toner image can be transferred to the copy paper and the amount of residual toner on the surface of the image bearing member can be reduced during printing, so the function of the cleaning device is normalized and the remaining toner image on the image bearing body can be reduced. All remaining toner is removed by cleaning, and a good copy sheet with no image defects can be obtained.

[Brief explanation of the drawing]

Figure 1 is a schematic configuration diagram of a copying machine according to the present invention, Figure 2 is a diagram showing the operation panel of the copying machine, Figure @3 is a block diagram of the present invention, and Figures 4 and 7 are FIG. 2 is a flowchart showing the processing procedure. (1) - Copying machine (2)...Photosensitive drum (6)...Transfer charger (9)...Magnetic brush cleaning device (40)
...Main motor rotation control circuit 2l- (44) ...Jam detection circuit (P) ...Copy paper applicant Minolta Camera Co., Ltd. 22- Dirt 3 Figure 4 - Figure [Co., Ltd.] ■ Electricity ■ Y IA setting Q [Phase] To ■ 71-[3rd generation input (negative tree annoying ■ Over $7? [Phase] ON [Phase] ■ Soft type % type % [] () Fig. 5 7 Figure

Claims (1)

[Claims] 1. In a powder image transfer type electronic copying machine which is equipped with a means for detecting a jam in the copying machine and a means for releasing the jam, and rotates the fΦ111 holder for a predetermined period of time when the power is turned on,
Control of a copying machine, characterized in that when a jam is released and the power is turned on, the toner remaining on the surface of the image carrier without being transferred is transferred to the copy paper, and then cleaning is performed. Method.